KSZ9021RL/RN Gigabit Ethernet Transceiver with RGMII Support Revision 1.2 General Description Features The KSZ9021RL is a completely integrated triple speed • Single-chip 10/100/1000Mbps IEEE 802.3 compliant (10Base-T/100Base-TX/1000Base-T) Ethernet Physical Ethernet Transceiver Layer Transceiver for transmission and reception of data • RGMII interface compliant to RGMII Version 1.3 over standard CAT-5 unshielded twisted pair (UTP) cable. • RGMII I/Os with 3.3V/2.5V tolerant and programmable The KSZ9021RL provides the Reduced Gigabit Media timings to adjust and correct delays on both Tx and Rx Independent Interface (RGMII) for direct connection to paths RGMII MACs in Gigabit Ethernet Processors and Switches • Auto-negotiation to automatically select the highest link for data transfer at 10/100/1000Mbps speed. up speed (10/100/100Mbps) and duplex (half/full) The KSZ9021RL reduces board cost and simplifies board • On-chip termination resistors for the differential pairs layout by using on-chip termination resistors for the four • On-chip LDO controller to support single 3.3V supply differential pairs and by integrating a LDO controller to operation – requires only external FET to generate 1.2V drive a low cost MOSFET to supply the 1.2V core. for the core The KSZ9021RL provides diagnostic features to facilitate • Jumbo frame support up to 16KB system bring-up and debugging in production testing and in product deployment. Parametric NAND tree support • 125MHz Reference Clock Output enables fault detection between KSZ9021 I/Os and board. • Programmable LED outputs for link, activity and speed Micrel LinkMD® TDR-based cable diagnostics permit • Baseline Wander Correction identification of faulty copper cabling. Remote and local • LinkMD® TDR-based cable diagnostics for identification loopback functions provide verification of analog and of faulty copper cabling digital data paths. • Parametric NAND Tree support for fault detection The KSZ9021RL is available in a 64-pin, lead-free E-LQFP between chip I/Os and board. package, and is offered as the KSZ9021RN in the smaller 48-pin QFN package (See Ordering Information). • Loopback modes for diagnostics ____________________________________________________________________________________________________________ Functional Diagram RGMII 10E/1t0h0eR/r1nG0eM0t 0IMI MACbps MMDanCa g/ eMmDeIOnt KSZ9021RL/RN On-chip Termination Resistors Magnetics CoRnJn-e4c5tor M e111d000iB00aB0a TBsayesape-sTee-Ts-T:X LDO Controller VIN VOUT 3.3VA 1.2V (for core voltages) LinkMD is a registered trademark of Micrel, Inc. Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com February 13, 2014 Revision 1.2

Micrel, Inc. KSZ9021RL/RN More Features Applications • Automatic MDI/MDI-X crossover for detection and • Laser/Network printer correction of pair swap at all speeds of operation • Network attached storage (NAS) • Automatic detection and correction of pair swap, pair • Network server skew and pair polarity • Gigabit LAN on motherboard (GLOM) • MDC/MDIO Management Interface for PHY register • Broadband gateway configuration • Gigabit SOHO/SMB router • Interrupt pin option • IPTV • Power down and power saving modes • IP Set-top box • Operating Voltages • Game console Core: 1.2V (external FET or regulator) • Triple-play (data, voice, video) media center I/O: 3.3V or 2.5V • Media converter Transceiver: 3.3V • Available packages 64-pin E-LQFP (10mm x 10mm): KSZ9021RL 48-pin QFN (7mm x 7mm): KSZ9021RN Ordering Information Part Number Temp. Range Package Lead Finish Description KSZ9021RL 0°C to +70°C 64-Pin E-LQFP Pb-Free RGMII, Commercial Temperature, 64-E-LQFP KSZ9021RLI (1) –40°C to +85°C 64-Pin E-LQFP Pb-Free RGMII, Industrial Temperature, 64-E-LQFP KSZ9021RN 0°C to +70°C 48-Pin QFN Pb-Free RGMII, Commercial Temperature, 48-QFN KSZ9021RNI (1) –40°C to +85°C 48-Pin QFN Pb-Free RGMII, Industrial Temperature, 48-QFN Note: 1. Contact factory for availability. February 13, 2014 2 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Revision History Revision Date Summary of Changes 1.0 1/16/09 Data sheet created. 1.1 10/13/09 Updated current consumption in Electrical Characteristics section. Corrected data sheet omission of register 1 bit 8 for 1000Base-T Extended Status information. Added the following register bits to provide further power saving during software power down: Tri- state all digital I/Os (reg. 258.7), LDO disable (reg. 263.15), Low frequency oscillator mode (reg. 263.8). Added KSZ9021RN device and updated entire data sheet accordingly. Added 48-Pin QFN package information. 1.2 2/13/14 Added RGMII Pad Skew Registers section. Corrected pad skew steps in Registers 260 (104h) and 261 (105h). Datasheet values are incorrect. There is no change to the silicon. Added Register 262 (106h) for RGMII TX Data Pad Skew. Updated boilerplate. February 13, 2014 3 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Contents Pin Configuration – KSZ9021RL .......................................................................................................................................... 8 Pin Description – KSZ9021RL .............................................................................................................................................. 9 Strapping Options – KSZ9021RL ....................................................................................................................................... 14 Pin Configuration – KSZ9021RN........................................................................................................................................ 15 Pin Description – KSZ9021RN ........................................................................................................................................... 16 Strapping Options – KSZ9021RN ...................................................................................................................................... 21 Functional Overview ........................................................................................................................................................... 22 Functional Description: 10Base-T/100Base-TX Transceiver .......................................................................................... 23 100Base-TX Transmit ....................................................................................................................................................... 23 100Base-TX Receive ........................................................................................................................................................ 23 Scrambler/De-scrambler (100Base-TX only) .................................................................................................................... 23 10Base-T Transmit ........................................................................................................................................................... 23 10Base-T Receive ............................................................................................................................................................ 23 Functional Description: 1000Base-T Transceiver............................................................................................................ 24 Analog Echo Cancellation Circuit ..................................................................................................................................... 24 Automatic Gain Control (AGC) ......................................................................................................................................... 24 Analog-to-Digital Converter (ADC) ................................................................................................................................... 24 Timing Recovery Circuit .................................................................................................................................................... 25 Adaptive Equalizer ............................................................................................................................................................ 25 Trellis Encoder and Decoder ............................................................................................................................................ 25 Functional Description: 10/100/1000 Transceiver Features ........................................................................................... 25 Auto MDI/MDI-X ................................................................................................................................................................ 25 Pair- Swap, Alignment, and Polarity Check ...................................................................................................................... 26 Wave Shaping, Slew Rate Control and Partial Response ................................................................................................ 26 PLL Clock Synthesizer ...................................................................................................................................................... 26 Auto-Negotiation ................................................................................................................................................................. 26 RGMII Interface .................................................................................................................................................................... 28 RGMII Signal Definition .................................................................................................................................................... 29 RGMII Signal Diagram ...................................................................................................................................................... 29 RGMII Pad Skew Registers .............................................................................................................................................. 30 RGMII In-band Status ....................................................................................................................................................... 32 MII Management (MIIM) Interface ....................................................................................................................................... 32 Interrupt (INT_N) .................................................................................................................................................................. 32 LED Mode ............................................................................................................................................................................. 33 Single LED Mode .............................................................................................................................................................. 33 Tri-color Dual LED Mode .................................................................................................................................................. 33 NAND Tree Support ............................................................................................................................................................ 34 Power Management ............................................................................................................................................................ 35 Power Saving Mode .......................................................................................................................................................... 35 Software Power Down Mode ............................................................................................................................................ 35 Chip Power Down Mode ................................................................................................................................................... 35 Register Map ........................................................................................................................................................................ 35 February 13, 2014 4 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Register Description ........................................................................................................................................................... 36 IEEE Defined Registers .................................................................................................................................................... 36 Vendor Specific Registers ................................................................................................................................................ 43 Extended Registers .......................................................................................................................................................... 45 Absolute Maximum Ratings ............................................................................................................................................... 48 Operating Ratings ............................................................................................................................................................... 48 Electrical Characteristics ................................................................................................................................................... 48 Timing Diagrams ................................................................................................................................................................. 50 RGMII Timing .................................................................................................................................................................... 50 Auto-Negotiation Timing ................................................................................................................................................... 51 MDC/MDIO Timing ........................................................................................................................................................... 52 Reset Timing ..................................................................................................................................................................... 53 Reset Circuit ........................................................................................................................................................................ 53 Reference Circuits – LED Strap-in Pins ............................................................................................................................ 54 Reference Clock – Connection and Selection .................................................................................................................. 55 Magnetics Specification ..................................................................................................................................................... 55 Package Information ........................................................................................................................................................... 56 February 13, 2014 5 Revision 1.2

Micrel, Inc. KSZ9021RL/RN List of Figures Figure 1. KSZ9021RL/RN Block Diagram ............................................................................................................................ 22 Figure 2. KSZ9021RL/RN 1000Base-T Block Diagram – Single Channel .......................................................................... 24 Figure 3. Auto-Negotiation Flow Chart ................................................................................................................................. 27 Figure 4. KSZ9021RL/RN RGMII Interface .......................................................................................................................... 29 Figure 5. RGMII v1.3 Specification (Figure 2 – Multiplexing and Timing Diagram) ............................................................. 50 Figure 6. Auto-Negotiation Fast Link Pulse (FLP) Timing ................................................................................................... 51 Figure 7. MDC/MDIO Timing ................................................................................................................................................ 52 Figure 8. Reset Timing ......................................................................................................................................................... 53 Figure 9. Recommended Reset Circuit ................................................................................................................................ 53 Figure 10. Recommended Reset Circuit for Interfacing with CPU/FPGA Reset Output ..................................................... 54 Figure 11. Reference Circuits for LED Strapping Pins......................................................................................................... 54 Figure 12. 25MHz Crystal/Oscillator Reference Clock Connection ..................................................................................... 55 February 13, 2014 6 Revision 1.2

Micrel, Inc. KSZ9021RL/RN List of Tables Table 1. MDI/MDI-X Pin Mapping ........................................................................................................................................ 25 Table 2. Auto-Negotiation Timers ........................................................................................................................................ 28 Table 3. RGMII Signal Definition .......................................................................................................................................... 29 Table 4. RGMII Pad Skew Registers ................................................................................................................................... 30 Table 5. Absolute Delay for 4-Bit Pad Skew Setting ............................................................................................................ 31 Table 6. RGMII In-Band Status ............................................................................................................................................ 32 Table 7. MII Management Frame Format – for KSZ9021RL/RN ......................................................................................... 32 Table 8. Single LED Mode – Pin Definition .......................................................................................................................... 33 Table 9. Tri-color Dual LED Mode – Pin Definition .............................................................................................................. 33 Table 10. NAND Tree Test Pin Order – for KSZ9021RL ..................................................................................................... 34 Table 11. NAND Tree Test Pin Order – for KSZ9021RN .................................................................................................... 34 Table 12. RGMII v1.3 Specification (Timing Specifics from Table 2) .................................................................................. 50 Table 13. Auto-Negotiation Fast Link Pulse (FLP) Timing Parameters ............................................................................... 51 Table 14. MDC/MDIO Timing Parameters ........................................................................................................................... 52 Table 15. Reset Timing Parameters .................................................................................................................................... 53 Table 16. Reference Crystal/Clock Selection Criteria .......................................................................................................... 55 Table 17. Magnetics Selection Criteria ................................................................................................................................ 55 Table 18. Qualified Single Port 10/100/1000 Magnetics ...................................................................................................... 55 February 13, 2014 7 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pin Configuration – KSZ9021RL 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 AVDDH AGNDH_BG ISET AVDDH XI XO AVDDL_PLL LDO_O RESET_N K125_NDO /LED_MODE DVDDL VSS DVDDL INT_N COL MDIO 1 TXRXP_A CL MDC 48 2 TXRXM_A CRS 47 RX_CLK / 3 AGNDH PHYAD2 46 4 AVDDL RX_ER 45 5 AVDDL DVDDH 44 RX_DV / 6 AVDDH CLK125_EN 43 RXD0 / 7 TXRXP_B MODE0 42 RXD1 / 8 TXRXM_B Exposed Pad MODE1 41 on bottom of chip 9 AGNDH DVDDL 40 10 TXRXP_C VSS 39 RXD2 / 11 TXRXM_C MODE2 38 12 AVDDL DVDDH 37 RXD3 / 13 AVDDL MODE3 36 14 TXRXP_D DVDDL 35 15 TXRXM_D VSS 34 16 AVDDH TX_EN 33 VSS VSS LED2 / PHYAD1 DVDDH LED1 / PHYAD0 DVDDL VSS TXD0 TXD1 TXD2 TXD3 VSS DVDDL DVDDH TX_ER GTX_CLK 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 64-Pin E-LQFP (Top View) February 13, 2014 8 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pin Description – KSZ9021RL Pin Number Pin Name Type(1) Pin Function 1 TXRXP_A I/O Media Dependent Interface[0], positive signal of differential pair 1000Base-T Mode: TXRXP_A corresponds to BI_DA+ for MDI configuration and BI_DB+ for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXP_A is the positive transmit signal (TX+) for MDI configuration and the positive receive signal (RX+) for MDI-X configuration, respectively. 2 TXRXM_A I/O Media Dependent Interface[0], negative signal of differential pair 1000Base-T Mode: TXRXM_A corresponds to BI_DA- for MDI configuration and BI_DB- for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXM_A is the negative transmit signal (TX-) for MDI configuration and the negative receive signal (RX-) for MDI-X configuration, respectively. 3 AGNDH Gnd Analog ground 4 AVDDL P 1.2V analog VDD 5 AVDDL P 1.2V analog VDD 6 AVDDH P 3.3V analog VDD 7 TXRXP_B I/O Media Dependent Interface[1], positive signal of differential pair 1000Base-T Mode: TXRXP_B corresponds to BI_DB+ for MDI configuration and BI_DA+ for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXP_B is the positive receive signal (RX+) for MDI configuration and the positive transmit signal (TX+) for MDI-X configuration, respectively. 8 TXRXM_B I/O Media Dependent Interface[1], negative signal of differential pair 1000Base-T Mode: TXRXM_B corresponds to BI_DB- for MDI configuration and BI_DA- for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXM_B is the negative receive signal (RX-) for MDI configuration and the negative transmit signal (TX-) for MDI-X configuration, respectively. 9 AGNDH Gnd Analog ground 10 TXRXP_C I/O Media Dependent Interface[2], positive signal of differential pair 1000Base-T Mode: TXRXP_C corresponds to BI_DC+ for MDI configuration and BI_DD+ for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXP_C is not used. 11 TXRXM_C I/O Media Dependent Interface[2], negative signal of differential pair 1000Base-T Mode: TXRXM_C corresponds to BI_DC- for MDI configuration and BI_DD- for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXM_C is not used. 12 AVDDL P 1.2V analog VDD February 13, 2014 9 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pin Number Pin Name Type(1) Pin Function 13 AVDDL P 1.2V analog VDD 14 TXRXP_D I/O Media Dependent Interface[3], positive signal of differential pair 1000Base-T Mode: TXRXP_D corresponds to BI_DD+ for MDI configuration and BI_DC+ for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXP_D is not used. 15 TXRXM_D I/O Media Dependent Interface[3], negative signal of differential pair 1000Base-T Mode: TXRXM_D corresponds to BI_DD- for MDI configuration and BI_DC- for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXM_D is not used. 16 AVDDH P 3.3V analog VDD 17 VSS Gnd Digital ground 18 VSS Gnd Digital ground 19 LED2 / I/O LED Output: Programmable LED2 Output / PHYAD1 Config Mode: The pull-up/pull-down value is latched as PHYAD[1] during power-up/reset. See “Strapping Options” section for details. The LED2 pin is programmed by the LED_MODE strapping option (pin 55), and is defined as follows. Single LED Mode Link Pin State LED Definition Link off H OFF Link on (any speed) L ON Tri-color Dual LED Mode Pin State LED Definition Link / Activity LED2 LED1 LED2 LED1 Link off H H OFF OFF 1000 Link / No Activity L H ON OFF 1000 Link / Activity (RX, TX) Toggle H Blinking OFF 100 Link / No Activity H L OFF ON 100 Link / Activity (RX, TX) H Toggle OFF Blinking 10 Link / No Activity L L ON ON 10 Link / Activity (RX, TX) Toggle Toggle Blinking Blinking For Tri-color Dual LED Mode, LED2 works in conjunction with LED1 (pin 21) to indicate 10 Mbps Link and Activity. 20 DVDDH P 3.3V/2.5V digital VDD February 13, 2014 10 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pin Number Pin Name Type(1) Pin Function 21 LED1 / I/O LED Output: Programmable LED1 Output / PHYAD0 Config Mode: The pull-up/pull-down value is latched as PHYAD[0] during power-up/reset. See “Strapping Options” section for details. The LED1 pin is programmed by the LED_MODE strapping option (pin 55), and is defined as follows. Single LED Mode Activity Pin State LED Definition No Activity H OFF Activity (RX, TX) Toggle Blinking Tri-color Dual LED Mode Pin State LED Definition Link / Activity LED2 LED1 LED2 LED1 Link off H H OFF OFF 1000 Link / No Activity L H ON OFF 1000 Link / Activity (RX, TX) Toggle H Blinking OFF 100 Link / No Activity H L OFF ON 100 Link / Activity (RX, TX) H Toggle OFF Blinking 10 Link / No Activity L L ON ON 10 Link / Activity (RX, TX) Toggle Toggle Blinking Blinking For Tri-color Dual LED Mode, LED1 works in conjunction with LED2 (pin 19) to indicate 10 Mbps Link and Activity. 22 DVDDL P 1.2V digital VDD 23 VSS Gnd Digital ground 24 TXD0 I RGMII Mode: RGMII TD0 (Transmit Data 0) Input 25 TXD1 I RGMII Mode: RGMII TD1 (Transmit Data 1) Input 26 TXD2 I RGMII Mode: RGMII TD2 (Transmit Data 2) Input 27 TXD3 I RGMII Mode: RGMII TD3 (Transmit Data 3) Input 28 VSS Gnd Digital ground 29 DVDDL P 1.2V digital VDD 30 DVDDH P 3.3V/2.5V digital VDD 31 TX_ER I RGMII Mode: This pin is not used and should be left as a no connect. 32 GTX_CLK I RGMII Mode: RGMII TXC (Transmit Reference Clock) Input 33 TX_EN I RGMII Mode: RGMII TX_CTL (Transmit Control) Input 34 VSS Gnd Digital ground 35 DVDDL P 1.2V digital VDD February 13, 2014 11 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pin Number Pin Name Type(1) Pin Function 36 RXD3 / I/O RGMII Mode: RGMII RD3 (Receive Data 3) Output / MODE3 Config Mode: The pull-up/pull-down value is latched as MODE3 during power-up/reset. See “Strapping Options” section for details. 37 DVDDH P 3.3V/2.5V digital VDD 38 RXD2 / I/O RGMII Mode: RGMII RD2 (Receive Data 2) Output / MODE2 Config Mode: The pull-up/pull-down value is latched as MODE2 during power-up/reset. See “Strapping Options” section for details. 39 VSS Gnd Digital ground 40 DVDDL P 1.2V digital VDD 41 RXD1 / I/O RGMII Mode: RGMII RD1 (Receive Data 1) Output / MODE1 Config Mode: The pull-up/pull-down value is latched as MODE1 during power-up/reset. See “Strapping Options” section for details. 42 RXD0 / I/O RGMII Mode: RGMII RD0 (Receive Data 0) Output / MODE0 Config Mode: The pull-up/pull-down value is latched as MODE0 during power-up/reset. See “Strapping Options” section for details. 43 RX_DV / I/O RGMII Mode: RGMII RX_CTL (Receive Control) Output / CLK125_EN Config Mode: Latched as CLK125_NDO Output Enable during power-up/reset. See “Strapping Options” section for details. 44 DVDDH P 3.3V/2.5V digital VDD 45 RX_ER O RGMII Mode: This pin is not used and should be left as a no connect. 46 RX_CLK / I/O RGMII Mode: RGMII RXC (Receive Reference Clock) Output / PHYAD2 Config Mode: The pull-up/pull-down value is latched as PHYAD[2] during power-up/reset. See “Strapping Options” section for details. 47 CRS O RGMII Mode: This pin is not used and should be left as a no connect. 48 MDC Ipu Management Data Clock Input This pin is the input reference clock for MDIO (pin 49). 49 MDIO Ipu/O Management Data Input/Output This pin is synchronous to MDC (pin 48) and requires an external pull-up resistor to 3.3V/2.5V digital VDD in a range from 1.0kΩ to 4.7kΩ. 50 COL O RGMII Mode: This pin is not used and should be left as a no connect. 51 INT_N O Interrupt Output This pin provides a programmable interrupt output and requires an external pull-up resistor to 3.3V/2.5V digital VDD in a range from 1.0kΩ to 4.7kΩ when active low. Register 1Bh is the Interrupt Control/Status Register for programming the interrupt conditions and reading the interrupt status. Register 1Fh bit 14 sets the interrupt output to active low (default) or active high. 52 DVDDL P 1.2V digital VDD 53 VSS Gnd Digital ground 54 DVDDL P 1.2V digital VDD 55 CLK125_NDO / I/O 125MHz Clock Output This pin provides a 125MHz reference clock output option for use by the MAC. / LED_MODE Config Mode: The pull-up/pull-down value is latched as LED_MODE during power-up/reset. See “Strapping Options” section for details. February 13, 2014 12 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pin Number Pin Name Type(1) Pin Function 56 RESET_N Ipu Chip Reset (active low) Hardware pin configurations are strapped-in at the de-assertion (rising edge) of RESET_N. See “Strapping Options” section for more details. 57 LDO_O O On-chip 1.2V LDO Controller Output This pin drives the input gate of a P-channel MOSFET to generate 1.2V for the chip’s core voltages. If 1.2V is provided by the system and this pin is not used, it can be left floating. 58 AVDDL_PLL P 1.2V analog VDD for PLL 59 XO O 25MHz Crystal feedback This pin is a no connect if oscillator or external clock source is used. 60 XI I Crystal / Oscillator / External Clock Input 25MHz ±50ppm tolerance 61 AVDDH P 3.3V analog VDD 62 ISET I/O Set transmit output level Connect a 4.99KΩ 1% resistor to ground on this pin. 63 AGNDH_BG Gnd Analog ground 64 AVDDH P 3.3V analog VDD E-PAD E-PAD Gnd Exposed Pad on bottom of chip Connect E-PAD to ground. Note: 1. P = Power supply. Gnd = Ground. I = Input. O = Output. I/O = Bi-directional. Ipu = Input with internal pull-up. Ipu/O = Input with internal pull-up / Output. February 13, 2014 13 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Strapping Options – KSZ9021RL Pin Number Pin Name Type(1) Pin Function 46 PHYAD2 I/O The PHY Address, PHYAD[2:0], is latched at power-up/reset and is configurable to any value from 1 to 7. Each PHY address bit is configured as follows: 19 PHYAD1 I/O Pull-up = 1 21 PHYAD0 I/O Pull-down = 0 PHY Address bits [4:3] are always set to ‘00’. 36 MODE3 I/O The MODE[3:0] strap-in pins are latched at power-up/reset and are defined as follows: 38 MODE2 I/O 41 MODE1 I/O MODE[3:0] Mode 42 MODE0 I/O 0000 Reserved – not used 0001 Reserved – not used 0010 Reserved – not used 0011 Reserved – not used 0100 NAND Tree Mode 0101 Reserved – not used 0110 Reserved – not used 0111 Chip Power Down Mode 1000 Reserved – not used 1001 Reserved – not used 1010 Reserved – not used 1011 Reserved – not used 1100 RGMII Mode – advertise 1000Base-T full-duplex only 1101 RGMII Mode – advertise 1000Base-T full and half-duplex only 1110 RGMII Mode – advertise all capabilities (10/100/1000 speed half/full duplex),except 1000Base-T half-duplex 1111 RGMII Mode – advertise all capabilities (10/100/1000 speed half/full duplex) 43 CLK125_EN I/O CLK125_EN is latched at power-up/reset and is defined as follows: Pull-up = Enable 125MHz Clock Output Pull-down = Disable 125MHz Clock Output Pin 55 (CLK125_NDO) provides the 125MHz reference clock output option for use by the MAC. 55 LED_MODE I/O LED_MODE is latched at power-up/reset and is defined as follows: Pull-up = Single LED Mode Pull-down = Tri-color Dual LED Mode Note: 1. I/O = Bi-directional. Pin strap-ins are latched during power-up or reset. In some systems, the MAC receive input pins may be driven during power-up or reset, and consequently cause the PHY strap-in pins on the RGMII signals to be latched to the incorrect configuration. In this case, it is recommended to add external pull-ups/pull-downs on the PHY strap-in pins to ensure the PHY is configured to the correct pin strap-in mode. February 13, 2014 14 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pin Configuration – KSZ9021RN O / ISET AVDDH XI XO AVDDL_PLL LDO_O RESET_N CLK125_NDLED_MODE DVDDH DVDDL INT_N MDIO 48 47 46 45 44 43 42 41 40 39 38 37 AVDDH 1 36 MDC RX_CLK / TXRXP_A 2 35 PHYAD2 TXRXM_A 3 34 DVDDH RX_DV / AVDDL 4 33 CLK125_EN RXD0 / TXRXP_B 5 32 MODE0 RXD1 / TXRXM_B 6 Paddle Ground 31 MODE1 (on bottom of chip) TXRXP_C 7 30 DVDDL TXRXM_C 8 29 VSS RXD2 / AVDDL 9 28 MODE2 RXD3 / TXRXP_D 10 27 MODE3 TXRXM_D 11 26 DVDDL AVDDH 12 25 TX_EN 13 14 15 16 17 18 19 20 21 22 23 24 VSS_PS DVDDL LED2 / PHYAD1 DVDDH LED1 / PHYAD0 DVDDL TXD0 TXD1 TXD2 TXD3 DVDDL GTX_CLK 48-Pin QFN (Top View) February 13, 2014 15 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pin Description – KSZ9021RN Pin Number Pin Name Type(1) Pin Function 1 AVDDH P 3.3V analog VDD 2 TXRXP_A I/O Media Dependent Interface[0], positive signal of differential pair 1000Base-T Mode: TXRXP_A corresponds to BI_DA+ for MDI configuration and BI_DB+ for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXP_A is the positive transmit signal (TX+) for MDI configuration and the positive receive signal (RX+) for MDI-X configuration, respectively. 3 TXRXM_A I/O Media Dependent Interface[0], negative signal of differential pair 1000Base-T Mode: TXRXM_A corresponds to BI_DA- for MDI configuration and BI_DB- for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXM_A is the negative transmit signal (TX-) for MDI configuration and the negative receive signal (RX-) for MDI-X configuration, respectively. 4 AVDDL P 1.2V analog VDD 5 TXRXP_B I/O Media Dependent Interface[1], positive signal of differential pair 1000Base-T Mode: TXRXP_B corresponds to BI_DB+ for MDI configuration and BI_DA+ for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXP_B is the positive receive signal (RX+) for MDI configuration and the positive transmit signal (TX+) for MDI-X configuration, respectively. 6 TXRXM_B I/O Media Dependent Interface[1], negative signal of differential pair 1000Base-T Mode: TXRXM_B corresponds to BI_DB- for MDI configuration and BI_DA- for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXM_B is the negative receive signal (RX-) for MDI configuration and the negative transmit signal (TX-) for MDI-X configuration, respectively. 7 TXRXP_C I/O Media Dependent Interface[2], positive signal of differential pair 1000Base-T Mode: TXRXP_C corresponds to BI_DC+ for MDI configuration and BI_DD+ for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXP_C is not used. 8 TXRXM_C I/O Media Dependent Interface[2], negative signal of differential pair 1000Base-T Mode: TXRXM_C corresponds to BI_DC- for MDI configuration and BI_DD- for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXM_C is not used. 9 AVDDL P 1.2V analog VDD February 13, 2014 16 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pin Number Pin Name Type(1) Pin Function 10 TXRXP_D I/O Media Dependent Interface[3], positive signal of differential pair 1000Base-T Mode: TXRXP_D corresponds to BI_DD+ for MDI configuration and BI_DC+ for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXP_D is not used. 11 TXRXM_D I/O Media Dependent Interface[3], negative signal of differential pair 1000Base-T Mode: TXRXM_D corresponds to BI_DD- for MDI configuration and BI_DC- for MDI-X configuration, respectively. 10Base-T/100Base-TX Mode: TXRXM_D is not used. 12 AVDDH P 3.3V analog VDD 13 VSS_PS Gnd Digital ground 14 DVDDL P 1.2V digital VDD 15 LED2 / I/O LED Output: Programmable LED2 Output / PHYAD1 Config Mode: The pull-up/pull-down value is latched as PHYAD[1] during power-up/reset. See “Strapping Options” section for details. The LED2 pin is programmed by the LED_MODE strapping option (pin 41), and is defined as follows. Single LED Mode Link Pin State LED Definition Link off H OFF Link on (any speed) L ON Tri-color Dual LED Mode Pin State LED Definition Link/Activity LED2 LED1 LED2 LED1 Link off H H OFF OFF 1000 Link / No Activity L H ON OFF 1000 Link / Activity (RX, TX) Toggle H Blinking OFF 100 Link / No Activity H L OFF ON 100 Link / Activity (RX, TX) H Toggle OFF Blinking 10 Link / No Activity L L ON ON 10 Link / Activity (RX, TX) Toggle Toggle Blinking Blinking For Tri-color Dual LED Mode, LED2 works in conjunction with LED1 (pin 17) to indicate 10 Mbps Link and Activity. 16 DVDDH P 3.3V/2.5V digital VDD February 13, 2014 17 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pin Number Pin Name Type(1) Pin Function 17 LED1 / I/O LED Output: Programmable LED1 Output / PHYAD0 Config Mode: The pull-up/pull-down value is latched as PHYAD[0] during power-up/reset. See “Strapping Options” section for details. The LED1 pin is programmed by the LED_MODE strapping option (pin 41), and is defined as follows. Single LED Mode Activity Pin State LED Definition No Activity H OFF Activity (RX, TX) Toggle Blinking Tri-color Dual LED Mode Pin State LED Definition Link/Activity LED2 LED1 LED2 LED1 Link off H H OFF OFF 1000 Link / No Activity L H ON OFF 1000 Link / Activity (RX, TX) Toggle H Blinking OFF 100 Link / No Activity H L OFF ON 100 Link / Activity (RX, TX) H Toggle OFF Blinking 10 Link / No Activity L L ON ON 10 Link / Activity (RX, TX) Toggle Toggle Blinking Blinking For Tri-color Dual LED Mode, LED1 works in conjunction with LED2 (pin 15) to indicate 10 Mbps Link and Activity. 18 DVDDL P 1.2V digital VDD 19 TXD0 I RGMII Mode: RGMII TD0 (Transmit Data 0) Input 20 TXD1 I RGMII Mode: RGMII TD1 (Transmit Data 1) Input 21 TXD2 I RGMII Mode: RGMII TD2 (Transmit Data 2) Input 22 TXD3 I RGMII Mode: RGMII TD3 (Transmit Data 3) Input 23 DVDDL P 1.2V digital VDD 24 GTX_CLK I RGMII Mode: RGMII TXC (Transmit Reference Clock) Input 25 TX_EN I RGMII Mode: RGMII TX_CTL (Transmit Control) Input 26 DVDDL P 1.2V digital VDD 27 RXD3 / I/O RGMII Mode: RGMII RD3 (Receive Data 3) Output / MODE3 Config Mode: The pull-up/pull-down value is latched as MODE3 during power-up/reset. See “Strapping Options” section for details. 28 RXD2 / I/O RGMII Mode: RGMII RD2 (Receive Data 2) Output / MODE2 Config Mode: The pull-up/pull-down value is latched as MODE2 during power-up/reset. See “Strapping Options” section for details. 29 VSS Gnd Digital ground 30 DVDDL P 1.2V digital VDD 31 RXD1 / I/O RGMII Mode: RGMII RD1 (Receive Data 1) Output / MODE1 Config Mode: The pull-up/pull-down value is latched as MODE1 during power-up/reset. See “Strapping Options” section for details. February 13, 2014 18 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pin Number Pin Name Type(1) Pin Function 32 RXD0 / I/O RGMII Mode: RGMII RD0 (Receive Data 0) Output / MODE0 Config Mode: The pull-up/pull-down value is latched as MODE0 during power-up/reset. See “Strapping Options” section for details. 33 RX_DV / I/O RGMII Mode: RGMII RX_CTL (Receive Control) Output / CLK125_EN Config Mode: Latched as CLK125_NDO Output Enable during power-up/ reset. See “Strapping Options” section for details. 34 DVDDH P 3.3V/2.5V digital VDD 35 RX_CLK / I/O RGMII Mode: RGMII RXC (Receive Reference Clock) Output / PHYAD2 Config Mode: The pull-up/pull-down value is latched as PHYAD[2] during power-up/reset. See “Strapping Options” section for details. 36 MDC Ipu Management Data Clock Input This pin is the input reference clock for MDIO (pin 37). 37 MDIO Ipu/O Management Data Input/Output This pin is synchronous to MDC (pin 36) and requires an external pull-up resistor to 3.3V/2.5V digital VDD in a range from 1.0kΩ to 4.7kΩ. 38 INT_N O Interrupt Output This pin provides a programmable interrupt output and requires an external pull-up resistor to 3.3V/2.5V digital VDD in a range from 1.0kΩ to 4.7kΩ when active low. Register 1Bh is the Interrupt Control/Status Register for programming the interrupt conditions and reading the interrupt status. Register 1Fh bit 14 sets the interrupt output to active low (default) or active high. 39 DVDDL P 1.2V digital VDD 40 DVDDH P 3.3V/2.5V digital VDD 41 CLK125_NDO / I/O 125MHz Clock Output This pin provides a 125MHz reference clock output option for use by the MAC. / LED_MODE Config Mode: The pull-up/pull-down value is latched as LED_MODE during power-up/reset. See “Strapping Options” section for details. 42 RESET_N Ipu Chip Reset (active low) Hardware pin configurations are strapped-in at the de-assertion (rising edge) of RESET_N. See “Strapping Options” section for more details. 43 LDO_O O On-chip 1.2V LDO Controller Output This pin drives the input gate of a P-channel MOSFET to generate 1.2V for the chip’s core voltages. If 1.2V is provided by the system and this pin is not used, it can be left floating. 44 AVDDL_PLL P 1.2V analog VDD for PLL 45 XO O 25MHz Crystal feedback This pin is a no connect if oscillator or external clock source is used. 46 XI I Crystal / Oscillator / External Clock Input 25MHz ±50ppm tolerance 47 AVDDH P 3.3V analog VDD 48 ISET I/O Set transmit output level Connect a 4.99kΩ 1% resistor to ground on this pin. PADDLE P_GND Gnd Exposed Paddle on bottom of chip Connect P_GND to ground. February 13, 2014 19 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Note: 1. P = Power supply. Gnd = Ground. I = Input. O = Output. I/O = Bi-directional. Ipu = Input with internal pull-up. Ipu/O = Input with internal pull-up / Output. February 13, 2014 20 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Strapping Options – KSZ9021RN Pin Number Pin Name Type(1) Pin Function 35 PHYAD2 I/O The PHY Address, PHYAD[2:0], is latched at power-up/reset and is configurable to any value from 1 to 7. Each PHY address bit is configured as follows: 15 PHYAD1 I/O Pull-up = 1 17 PHYAD0 I/O Pull-down = 0 PHY Address bits [4:3] are always set to ‘00’. 27 MODE3 I/O The MODE[3:0] strap-in pins are latched at power-up/reset and are defined as follows: 28 MODE2 I/O 31 MODE1 I/O MODE[3:0] Mode 32 MODE0 I/O 0000 Reserved – not used 0001 Reserved – not used 0010 Reserved – not used 0011 Reserved – not used 0100 NAND Tree Mode 0101 Reserved – not used 0110 Reserved – not used 0111 Chip Power Down Mode 1000 Reserved – not used 1001 Reserved – not used 1010 Reserved – not used 1011 Reserved – not used 1100 RGMII Mode – advertise 1000Base-T full-duplex only 1101 RGMII Mode – advertise 1000Base-T full and half-duplex only 1110 RGMII Mode – advertise all capabilities (10/100/1000 speed half/full duplex), except 1000Base-T half-duplex 1111 RGMII Mode – advertise all capabilities (10/100/1000 speed half/full duplex) 33 CLK125_EN I/O CLK125_EN is latched at power-up/reset and is defined as follows: Pull-up = Enable 125MHz Clock Output Pull-down = Disable 125MHz Clock Output Pin 41 (CLK125_NDO) provides the 125MHz reference clock output option for use by the MAC. 41 LED_MODE I/O LED_MODE is latched at power-up/reset and is defined as follows: Pull-up = Single LED Mode Pull-down = Tri-color Dual LED Mode Note: 1. I/O = Bi-directional. Pin strap-ins are latched during power-up or reset. In some systems, the MAC receive input pins may be driven during power-up or reset, and consequently cause the PHY strap-in pins on the RGMII signals to be latched to the incorrect configuration. In this case, it is recommended to add external pull-ups/pull-downs on the PHY strap-in pins to ensure the PHY is configured to the correct pin strap-in mode. February 13, 2014 21 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Functional Overview The KSZ9021RL/RN is a completely integrated triple speed (10Base-T/100Base-TX/1000Base-T) Ethernet Physical Layer Transceiver solution for transmission and reception of data over a standard CAT-5 unshielded twisted pair (UTP) cable. Its on-chip proprietary 1000Base-T transceiver and Manchester/MLT-3 signaling-based 10Base-T/100Base-TX transceivers are all IEEE 802.3 compliant. The KSZ9021RL/RN reduces board cost and simplifies board layout by using on-chip termination resistors for the four differential pairs and by integrating a LDO controller to drive a low cost MOSFET to supply the 1.2V core. On the copper media interface, the KSZ9021RL/RN can automatically detect and correct for differential pair misplacements and polarity reversals, and correct propagation delays and re-sync timing between the four differential pairs, as specified in the IEEE 802.3 standard for 1000Base-T operation. The KSZ9021RL/RN provides the RGMII interface for a direct and seamless connection to RGMII MACs in Gigabit Ethernet Processors and Switches for data transfer at 10/100/1000Mbps speed. The following figure shows a high-level block diagram of the KSZ9021RL/RN. PMA TX10/100/1000 Clock Reset Configurations PMA RX1000 PCS1000 MEDIA INTERFACE PMA RGMII RX100 Interface PCS100 PMA PCS10 RX10 LED AUTO DRIVERS NEGOTIATION Figure 1. KSZ9021RL/RN Block Diagram February 13, 2014 22 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Functional Description: 10Base-T/100Base-TX Transceiver 100Base-TX Transmit The 100Base-TX transmit function performs parallel to serial conversion, 4B/5B coding, scrambling, NRZ-to-NRZI conversion, and MLT-3 encoding and transmission. The circuitry starts with a parallel-to-serial conversion, which converts the RGMII data from the MAC into a 125MHz serial bit stream. The data and control stream is then converted into 4B/5B coding, followed by a scrambler. The serialized data is further converted from NRZ-to-NRZI format, and then transmitted in MLT-3 current output. The output current is set by an external 4.99kΩ 1% resistor for the 1:1 transformer ratio. The output signal has a typical rise/fall time of 4ns and complies with the ANSI TP-PMD standard regarding amplitude balance, overshoot, and timing jitter. The wave-shaped 10Base-T output is also incorporated into the 100Base-TX transmitter. 100Base-TX Receive The 100BASE-TX receiver function performs adaptive equalization, DC restoration, MLT-3-to-NRZI conversion, data and clock recovery, NRZI-to-NRZ conversion, de-scrambling, 4B/5B decoding, and serial-to-parallel conversion. The receiving side starts with the equalization filter to compensate for inter-symbol interference (ISI) over the twisted pair cable. Since the amplitude loss and phase distortion is a function of the cable length, the equalizer must adjust its characteristics to optimize performance. In this design, the variable equalizer makes an initial estimation based on comparisons of incoming signal strength against some known cable characteristics, and then tunes itself for optimization. This is an ongoing process and self-adjusts against environmental changes such as temperature variations. Next, the equalized signal goes through a DC restoration and data conversion block. The DC restoration circuit is used to compensate for the effect of baseline wander and to improve the dynamic range. The differential data conversion circuit converts the MLT-3 format back to NRZI. The slicing threshold is also adaptive. The clock recovery circuit extracts the 125MHz clock from the edges of the NRZI signal. This recovered clock is then used to convert the NRZI signal into the NRZ format. This signal is sent through the de-scrambler followed by the 4B/5B decoder. Finally, the NRZ serial data is converted to the RGMII format and provided as the input data to the MAC. Scrambler/De-scrambler (100Base-TX only) The purpose of the scrambler is to spread the power spectrum of the signal to reduce electromagnetic interference (EMI) and baseline wander. Transmitted data is scrambled through the use of an 11-bit wide linear feedback shift register (LFSR). The scrambler generates a 2047-bit non-repetitive sequence, and the receiver then de-scrambles the incoming data stream using the same sequence as at the transmitter. 10Base-T Transmit The output 10Base-T driver is incorporated into the 100Base-TX driver to allow transmission with the same magnetic. They are internally wave-shaped and pre-emphasized into typical outputs of 2.5V amplitude. The harmonic contents are at least 31 dB below the fundamental when driven by an all-ones Manchester-encoded signal. 10Base-T Receive On the receive side, input buffer and level detecting squelch circuits are employed. A differential input receiver circuit and a phase-locked loop (PLL) perform the decoding function. The Manchester-encoded data stream is separated into clock signal and NRZ data. A squelch circuit rejects signals with levels less than 300 mV or with short pulse widths in order to prevent noises at the receive inputs from falsely triggering the decoder. When the input exceeds the squelch limit, the PLL locks onto the incoming signal and the KSZ9021RL/RN decodes a data frame. The receiver clock is maintained active during idle periods in between receiving data frames. February 13, 2014 23 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Functional Description: 1000Base-T Transceiver The 1000Base-T transceiver is based on a mixed-signal/digital signal processing (DSP) architecture, which includes the analog front-end, digital channel equalizers, trellis encoders/decoders, echo cancellers, cross-talk cancellers, precision clock recovery scheme, and power efficient line drivers. The following figure shows a high-level block diagram of a single channel of the 1000Base-T transceiver for one of the four differential pairs. OTHER XTAL Clk CHANNELS Generation Side-Stream Scrambler & TX Symbol Encoder Signal Transmit Block PCS State Machines LED Driver Pair Swap AHnyablroidg Echo Canceller NNENEXEXTXT TC C aCanancncecelellellelrerr Align& Unit Descr+ambler Baseline Decoder Wander Compensation AG RX- + FFE SLICER C ADC RX Signal Clock & Phase DFE Recovery MII MII Auto-Negotiation Management Registers Control PMA State Machines Figure 2. KSZ9021RL/RN 1000Base-T Block Diagram – Single Channel Analog Echo Cancellation Circuit In 1000Base-T mode, the analog echo cancellation circuit helps to reduce the near-end echo. This analog hybrid circuit relieves the burden of the ADC and the adaptive equalizer. This circuit is disabled in 10Base-T/100Base-TX mode. Automatic Gain Control (AGC) In 1000Base-T mode, the automatic gain control (AGC) circuit provides initial gain adjustment to boost up the signal level. This pre-conditioning circuit is used to improve the signal-to-noise ratio of the receive signal. Analog-to-Digital Converter (ADC) In 1000Base-T mode, the analog-to-digital converter (ADC) digitizes the incoming signal. ADC performance is essential to the overall performance of the transceiver. This circuit is disabled in 10Base-T/100Base-TX mode. February 13, 2014 24 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Timing Recovery Circuit In 1000Base-T mode, the mixed-signal clock recovery circuit, together with the digital phase locked loop, is used to recover and track the incoming timing information from the received data. The digital phase locked loop has very low long- term jitter to maximize the signal-to-noise ratio of the receive signal. The 1000Base-T slave PHY is required to transmit the exact receive clock frequency recovered from the received data back to the 1000Base-T master PHY. Otherwise, the master and slave will not be synchronized after long transmission. Additionally, this helps to facilitate echo cancellation and NEXT removal. Adaptive Equalizer In 1000Base-T mode, the adaptive equalizer provides the following functions: • Detection for partial response signaling • Removal of NEXT and ECHO noise • Channel equalization Signal quality is degraded by residual echo that is not removed by the analog hybrid and echo due to impedance mismatch. The KSZ9021RL/RN employs a digital echo canceller to further reduce echo components on the receive signal. In 1000Base-T mode, the data transmission and reception occurs simultaneously on all four pairs of wires (four channels). This results in high frequency cross-talk coming from adjacent wires. The KSZ9021RL/RN employs three NEXT cancellers on each receive channel to minimize the cross-talk induced by the other three channels. In 10Base-T/100Base-TX mode, the adaptive equalizer needs only to remove the inter-symbol interference and recover the channel loss from the incoming data. Trellis Encoder and Decoder In 1000Base-T mode, the transmitted 8-bit data is scrambled into 9-bit symbols and further encoded into 4D-PAM5 symbols. The initial scrambler seed is determined by the specific PHY address to reduce EMI when more than one KSZ9021RL/RN is used on the same board. On the receiving side, the idle stream is examined first. The scrambler seed, pair skew, pair order and polarity have to be resolved through the logic. The incoming 4D-PAM5 data is then converted into 9-bit symbols and then de-scrambled into 8-bit data. Functional Description: 10/100/1000 Transceiver Features Auto MDI/MDI-X The Automatic MDI/MDI-X feature eliminates the need to determine whether to use a straight cable or a crossover cable between the KSZ9021RL/RN and its link partner. This auto-sense function detects the MDI/MDI-X pair mapping from the link partner, and then assigns the MDI/MDI-X pair mapping of the KSZ9021RL/RN accordingly. The following table shows the KSZ9021RL/RN 10/100/1000 pin-out assignments for MDI/MDI-X pin mapping. MDI MDI-X Pin (RJ-45 pair) 1000Base-T 100Base-TX 10Base-T 1000Base-T 100Base-TX 10Base-T TXRXP/M_A (1,2) A+/- TX+/- TX+/- B+/- RX+/- RX+/- TXRXP/M_B (3,6) B+/- RX+/- RX+/- A+/- TX+/- TX+/- TXRXP/M_C (4,5) C+/- Not used Not used D+/- Not used Not used TXRXP/M_D (7,8) D+/- Not used Not used C+/- Not used Not used Table 1. MDI/MDI-X Pin Mapping Auto MDI/MDI-X is enabled by default. It is disabled by writing a one to register 28 (1Ch) bit 6. MDI and MDI-X mode is set by register 28 (1Ch) bit 7 if auto MDI/MDI-X is disabled. An isolation transformer with symmetrical transmit and receive data paths is recommended to support auto MDI/MDI-X. February 13, 2014 25 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pair- Swap, Alignment, and Polarity Check In 1000Base-T mode, the KSZ9021RL/RN • Detects incorrect channel order and automatically restore the pair order for the A, B, C, D pairs (four channels) • Supports 50 ±10ns difference in propagation delay between pairs of channels in accordance with the IEEE 802.3 standard, and automatically corrects the data skew so the corrected 4-pairs of data symbols are synchronized Incorrect pair polarities of the differential signals are automatically corrected for all speeds. Wave Shaping, Slew Rate Control and Partial Response In communication systems, signal transmission encoding methods are used to provide the noise-shaping feature and to minimize distortion and error in the transmission channel. • For 1000Base-T, a special partial response signaling method is used to provide the band-limiting feature for the transmission path. • For 100Base-TX, a simple slew rate control method is used to minimize EMI. • For 10Base-T, pre-emphasis is used to extend the signal quality through the cable. PLL Clock Synthesizer The KSZ9021RL/RN generates 125MHz, 25MHz and 10MHz clocks for system timing. Internal clocks are generated from the external 25MHz crystal or reference clock. Auto-Negotiation The KSZ9021RL/RN conforms to the auto-negotiation protocol, defined in Clause 28 of the IEEE 802.3 Specification. Auto-negotiation allows UTP (Unshielded Twisted Pair) link partners to select the highest common mode of operation. During auto-negotiation, link partners advertise capabilities across the UTP link to each other, and then compare their own capabilities with those they received from their link partners. The highest speed and duplex setting that is common to the two link partners is selected as the mode of operation. The following list shows the speed and duplex operation mode from highest to lowest. • Priority 1: 1000Base-T, full-duplex • Priority 2: 1000Base-T, half-duplex • Priority 3: 100Base-TX, full-duplex • Priority 4: 100Base-TX, half-duplex • Priority 5: 10Base-T, full-duplex • Priority 6: 10Base-T, half-duplex If auto-negotiation is not supported or the KSZ9021RL/RN link partner is forced to bypass auto-negotiation for 10Base-T and 100Base-TX modes, then the KSZ9021RL/RN sets its operating mode by observing the input signal at its receiver. This is known as parallel detection, and allows the KSZ9021RL/RN to establish a link by listening for a fixed signal protocol in the absence of auto-negotiation advertisement protocol. The auto-negotiation link up process is shown in the following flow chart. February 13, 2014 26 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Figure 3. Auto-Negotiation Flow Chart For 1000Base-T mode, auto-negotiation is required and always used to establish link. During 1000Base-T auto- negotiation, Master and Slave configuration is first resolved between link partners, and then link is established with the highest common capabilities between link partners. Auto-negotiation is enabled by default at power-up or after hardware reset. Afterwards, auto-negotiation can be enabled or disabled through register 0 bit 12. If auto-negotiation is disabled, then the speed is set by register 0 bits 6 and 13, and the duplex is set by register 0 bit 8. If the speed is changed on the fly, then the link goes down and either auto-negotiation or parallel detection will initiate until a common speed between KSZ9021RL/RN and its link partner is re-established for link. If link is already established, and there is no change of speed on the fly, then the changes will not take effect unless either auto-negotiation is restarted through register 0 bit 9, or a link down to link up transition occurs (i.e., disconnecting and reconnecting the cable). After auto-negotiation is completed, the link status is updated in register 1 and the link partner capabilities are updated in registers 5, 6, and 10. The auto-negotiation finite state machines employ interval timers to manage the auto-negotiation process. The duration of these timers under normal operating conditions are summarized in the following table. February 13, 2014 27 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Auto-Negotiation Interval Timers Time Duration Transmit Burst interval 16ms Transmit Pulse interval 68µs FLP detect minimum time 17.2µs FLP detect maximum time 185µs Receive minimum Burst interval 6.8ms Receive maximum Burst interval 112ms Data detect minimum interval 35.4µs Data detect maximum interval 95µs NLP test minimum interval 4.5ms NLP test maximum interval 30ms Link Loss time 52ms Break Link time 1480ms Parallel Detection wait time 830ms Link Enable wait time 1000ms Table 2. Auto-Negotiation Timers RGMII Interface The Reduced Gigabit Media Independent Interface (RGMII) is compliant with the RGMII Version 1.3 Specification. It provides a common interface between RGMII PHYs and MACs, and has the following key characteristics: • Pin count is reduced from 24 pins for the IEEE Gigabit Media Independent Interface (GMII) to 12 pins for RGMII. • All speeds (10Mbps, 100Mbps, and 1000Mbps) are supported at both half and full duplex. • Data transmission and reception are independent and belong to separate signal groups. • Transmit data and receive data are each 4-bit wide, a nibble. In RGMII operation, the RGMII pins function as follow: • The MAC sources the transmit reference clock, TXC, at 125MHz for 1000Mbps, 25MHz for 100Mbps and 2.5MHz for 10Mbps. • The PHY recovers and sources the receive reference clock, RXC, at 125MHz for 1000Mbps, 25MHz for 100Mbps and 2.5MHz for 10Mbps. • For 1000Base-T, the transmit data, TXD[3:0], is presented on both edges of TXC, and the received data, RXD[3:0], is clocked out on both edges of the recovered 125 MHz clock, RXC. • For 10Base-T/100Base-TX, the MAC will hold TX_CTL low until both PHY and MAC operate at the same speed. During the speed transition, the receive clock will be stretched on either positive or negative pulse to ensure that no clock glitch is presented to the MAC at any time. • TX_ER and RX_ER are combined with TX_EN and RX_DV, respectively, to form TX_CTL and RX_CTL. These two RGMII control signals are valid at the falling clock edge. After power-up or reset, the KSZ9021RL/RN is configured to RGMII mode if the MODE[3:0] strap-in pins are set to one of the RGMII mode capability options. See Strapping Options section for available options. The KSZ9021RL/RN has the option to output a low jitter 125MHz reference clock on the CLK125_NDO pin. This clock provides a lower cost reference clock alternative for RGMII MACs that require a 125MHz crystal or oscillator. The 125MHz clock output is enabled after power-up or reset if the CLK125_EN strap-in pin is pulled high. February 13, 2014 28 Revision 1.2

Micrel, Inc. KSZ9021RL/RN RGMII Signal Definition The following table describes the RGMII signals. Refer to the RGMII Version 1.3 Specification for more detailed information. RGMII RGMII Pin Type Pin Type Signal Name Signal Name (with respect (with respect Description (per spec) (per KSZ9021RL/RN) to PHY) to MAC) TXC GTX_CLK Input Output Transmit Reference Clock (125MHz for 1000Mbps, 25MHz for 100Mbps, 2.5MHz for 10Mbps) TX_CTL TX_EN Input Output Transmit Control TXD[3:0] TXD[3:0] Input Output Transmit Data [3:0] RXC RX_CLK Output Input Receive Reference Clock (125MHz for 1000Mbps, 25MHz for 100Mbps, 2.5MHz for 10Mbps) RX_CTL RX_DV Output Input Receive Control RXD[3:0] RXD[3:0] Output Input Receive Data [3:0] Table 3. RGMII Signal Definition RGMII Signal Diagram The KSZ9021RL/RN RGMII pin connections to the MAC are shown in the following figure. RGMII KSZ9021RL/RN Ethernet MAC GTX_CLK TXC TX_EN TX_CTL TXD[3:0] TXD[3:0] RX_CLK RXC RX_DV RX_CTL RXD[3:0] RXD[3:0] Figure 4. KSZ9021RL/RN RGMII Interface February 13, 2014 29 Revision 1.2

Micrel, Inc. KSZ9021RL/RN RGMII Pad Skew Registers Pad skew registers are available for all RGMII pins (clocks, control signals, and data bits) to provide programming options to adjust or correct the timing relationship for each RGMII pin. Because RGMII is a source-synchronous bus interface, the timing relationship needs to be maintained only within the RGMII pin’s respective timing group. • RGMII transmit timing group pins: GTX_CLK, TX_EN, TXD[3:0] • RGMII receive timing group pins: RX_CLK, RX_DV, RXD[3:0] The following three registers located at Extended Registers 260 (104h), 261 (105h), and 262 (106h) are provided for pad skew programming. Address Name Description Mode Default Register 260 (104h) – RGMII Clock and Control Pad Skew 260.15:12 rxc_pad_skew RGMII RXC PAD Skew Control (0.12ns/step) RW 0111 260.11:8 rxdv_pad_skew RGMII RX_CTL PAD Skew Control RW 0111 (0.12ns/step) 260.7:4 txc_pad_skew RGMII TXC PAD Skew Control (0.12ns/step) RW 0111 260.3:0 txen_pad_skew RGMII TX_CTL PAD Skew Control RW 0111 (0.12ns/step) Register 261 (105h) – RGMII RX Data Pad Skew 261.15:12 rxd3_pad_skew RGMII RXD3 PAD Skew Control (0.12ns/step) RW 0111 261.11:8 rxd2_pad_skew RGMII RXD2 PAD Skew Control (0.12ns/step) RW 0111 261.7:4 rxd1_pad_skew RGMII RXD1 PAD Skew Control (0.12ns/step) RW 0111 261.3:0 rxd0_pad_skew RGMII RXD0 PAD Skew Control (0.12ns/step) RW 0111 Register 262 (106h) – RGMII TX Data Pad Skew 262.15:12 txd3_pad_skew RGMII TXD3 PAD Skew Control (0.12ns/step) RW 0111 262.11:8 txd2_pad_skew RGMII TXD2 PAD Skew Control (0.12ns/step) RW 0111 262.7:4 txd1_pad_skew RGMII TXD1 PAD Skew Control (0.12ns/step) RW 0111 262.3:0 txd0_pad_skew RGMII TXD0 PAD Skew Control (0.12ns/step) RW 0111 Table 4. RGMII Pad Skew Registers The RGMII clocks, control signals, and data bits have 4-bit skew settings. Each register bit is approximately a 0.12ns step change. A single-bit decrement decreases the delay by approximately 0.12ns, while a single-bit increment increases the delay by approximately 0.12ns. The following table lists the approximate absolute delay for each pad skew (value) setting. February 13, 2014 30 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Pad Skew (value) Delay (ns) 0000 –0.84 0001 –0.72 0010 –0.60 0011 –0.48 0100 –0.36 0101 –0.24 0110 –0.12 0111 No delay adjustment (default value) 1000 +0.12 1001 +0.24 1010 +0.36 1011 +0.48 1100 +0.60 1101 +0.72 1110 +0.84 1111 +0.96 Table 5. Absolute Delay for 4-Bit Pad Skew Setting When computing the RGMII timing relationships, delays along the entire data path must be aggregated to determine the total delay to be used for comparison between RGMII pins within their respective timing group. For the transmit data path, total delay includes MAC output delay, MAC-to-PHY PCB routing delay, and PHY (KSZ9021RL/RN) input delay and skew setting (if any). For the receive data path, the total delay includes PHY (KSZ9021RL/RN) output delay, PHY-to-MAC PCB routing delay, and MAC input delay and skew setting (if any). After power-up or reset, the KSZ9021RL/RN defaults to the following timings at its RGMII I/O pins to support off-chip data- to-clock skew timing, as extended PCB trace run, according to the RGMII Version 1.3 Specification: • Transmit Inputs: GTX_CLK clock is in sync within ±500ps of TX_EN and TXD[3:0] • Receive outputs: RX_CLK clock is in sync within ±500ps of RX_DV and RXD[3:0] Alternatively, the KSZ9021RL/RN can be programmed to support RGMII v2.0 with the required data-to-clock skew implemented on-chip. If the delay is not implemented on the PCB and not programmed inside the MAC, the clock skew delay can be implemented via KSZ9021RL/RN registers 260 (104h), 261 (105h) and 262 (106h). These registers are accessed indirectly via the following registers: • Register 11 (Bh) // Extended Register – Control • Register 12 (Ch) // Extended Register – Data Write • Register 13 (Dh) // Extended Register – Data Read For the required data-to-clock delays, • For the RGMII transmit path, if there is no skew adjustment in the GMAC and also no skew on the PCB, set register 260 (104h) bits [7:0] to ‘F0’ to delay the GTX_CLK and speed up TXEN. • For the RGMII receive path, if there is no skew adjustment in the GMAC and also no skew on the PCB, set register 260 (104h) bits [15:8] to ‘F0’ to delay the RX_CLK and speed up RXDV. February 13, 2014 31 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Additionally, RXD[3:0] and TXD[3:0] can be sped up by 0.84ns by setting the 4 register bits for each data bit to 0x0h in register 261 (105h) and register 262 (106h), respectively. Effectively, the 0.96ns clock delays and -0.84ns data delays (negative means speed up) will produce a combined data-to- clock skew of 1.8ns. RGMII In-band Status The KSZ9021RL/RN can provide in-band status to the MAC during the inter-frame gap when RX_DV is de-asserted. RGMII in-band status is disabled by default. It is enabled by writing a one to extended register 256 (100h) bit 8. The in-band status is sent to the MAC using the RXD[3:0] data pins, and is described in the following table. RX_DV RXD3 RXD[2:1] RXD0 Duplex Status RX_CLK clock speed Link Status 0 0 = half-duplex 00 = 2.5MHz 0 = Link down (valid only when RX_DV 1 = full-duplex 01 = 25MHz 1 = Link up is low and register 256 10 = 125MHz bit 8 is set to 1) 11 = reserved Table 6. RGMII In-Band Status MII Management (MIIM) Interface The KSZ9021RL/RN supports the IEEE 802.3 MII Management Interface, also known as the Management Data Input/Output (MDIO) Interface. This interface allows upper-layer devices to monitor and control the state of the KSZ9021RL/RN. An external device with MIIM capability is used to read the PHY status and/or configure the PHY settings. Further detail on the MIIM interface can be found in Clause 22.2.4.5 of the IEEE 802.3 Specification. The MIIM interface consists of the following: • A physical connection that incorporates the clock line (MDC) and the data line (MDIO). • A specific protocol that operates across the aforementioned physical connection that allows an external controller to communicate with one or more KSZ9021RL/RN device. Each KSZ9021RL/RN device is assigned a PHY address between 1 and 7 by the PHYAD[2:0] strapping pins. • A 32 register address space to access the KSZ9021RL/RN IEEE Defined Registers, Vendor Specific Registers and Extended Registers. See Register Map section. The following table shows the MII Management frame format for the KSZ9021RL/RN. Preamble Start of Read/Write PHY REG TA Data Idle Frame OP Code Address Address Bits [15:0] Bits [4:0] Bits [4:0] Read 32 1’s 01 10 00AAA RRRRR Z0 DDDDDDDD_DDDDDDDD Z Write 32 1’s 01 01 00AAA RRRRR 10 DDDDDDDD_DDDDDDDD Z Table 7. MII Management Frame Format – for KSZ9021RL/RN Interrupt (INT_N) The INT_N pin is an optional interrupt signal that is used to inform the external controller that there has been a status update in the KSZ9021RL/RN PHY register. Bits [15:8] of register 27 (1Bh) are the interrupt control bits to enable and disable the conditions for asserting the INT_N signal. Bits [7:0] of register 27 (1Bh) are the interrupt status bits to indicate which interrupt conditions have occurred. The interrupt status bits are cleared after reading register 27 (1Bh). Bit 14 of register 31 (1Fh) sets the interrupt level to active high or active low. The default is active low. February 13, 2014 32 Revision 1.2

Micrel, Inc. KSZ9021RL/RN The MII management bus option gives the MAC processor complete access to the KSZ9021RL/RN control and status registers. Additionally, an interrupt pin eliminates the need for the processor to poll the PHY for status change. LED Mode The KSZ9021RL/RN provides two programmable LED output pins, LED2 and LED1, which are configurable to support two LED modes. The LED mode is configured by the LED_MODE strap-in pin. It is latched at power-up/reset and is defined as follows: • Pull-up: Single LED Mode • Pull-down: Tri-color Dual LED Mode Single LED Mode In Single LED Mode, the LED2 pin indicates the link status while the LED1 pin indicates the activity status, as shown in the following table. LED pin Pin State LED Definition Link/Activity H OFF Link off LED2 L ON Link on (any speed) H OFF No Activity LED1 Toggle Blinking Activity (RX, TX) Table 8. Single LED Mode – Pin Definition Tri-color Dual LED Mode In Tri-color Dual LED Mode, the Link and Activity status are indicated by the LED2 pin for 1000Base-T, by the LED1 pin for 100Base-TX, and by both LED2 and LED1 pin, working in conjunction, for 10Base-T. This is summarized in the following table. LED Pin LED Pin (State) (Definition) Link/Activity LED2 LED1 LED2 LED1 H H OFF OFF Link off L H ON OFF 1000 Link / No Activity Toggle H Blinking OFF 1000 Link / Activity (RX, TX) H L OFF ON 100 Link / No Activity H Toggle OFF Blinking 100 Link / Activity (RX, TX) L L ON ON 10 Link / No Activity Toggle Toggle Blinking Blinking 10 Link / Activity (RX, TX) Table 9. Tri-color Dual LED Mode – Pin Definition Each LED output pin can directly drive a LED with a series resistor (typically 220Ω to 470Ω). For activity indication, the LED output toggles at approximately 12.5Hz (80ms) to ensure visibility to the human eye. February 13, 2014 33 Revision 1.2

Micrel, Inc. KSZ9021RL/RN NAND Tree Support The KSZ9021RL/RN provides parametric NAND tree support for fault detection between chip I/Os and board. NAND tree mode is enabled at power-up/reset with the MODE[3:0] strap-in pins set to 0100. The following tables list the NAND tree pin order for KSZ9021RL and KSZ9021RN. Pin Description LED2 Input LED1 Input TXD0 Input TXD1 Input TXD2 Input TXD3 Input TX_ER Input GTX_CLK Input TX_EN Input RX_DV Input RX_ER Input RX_CLK Input CRS Input COL Input INT_N Input MDC Input MDIO Input CLK125_NDO Output Table 10. NAND Tree Test Pin Order – for KSZ9021RL Pin Description LED2 Input LED1 Input TXD0 Input TXD1 Input TXD2 Input TXD3 Input GTX_CLK Input TX_EN Input RX_DV Input RX_CLK Input INT_N Input MDC Input MDIO Input CLK125_NDO Output Table 11. NAND Tree Test Pin Order – for KSZ9021RN February 13, 2014 34 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Power Management The KSZ9021RL/RN offers the following power management modes: Power Saving Mode This mode is a KSZ9021RL/RN green feature to reduce power consumption when the cable is unplugged. It is in effect when auto-negotiation mode is enabled and the cable is disconnected (no link). Software Power Down Mode This mode is used to power down the KSZ9021RL/RN device when it is not in use after power-up. Power down mode is enabled by writing a one to register 0h bit 11. In the power down state, the KSZ9021RL/RN disables all internal functions, except for the MII management interface. The KSZ9021RL/RN exits power down mode after writing a zero to register 0h bit 11. Chip Power Down Mode This mode provides the lowest power state for the KSZ9021RL/RN when it is not in use and is mounted on the board. Chip power down mode is enabled at power-up/reset with the MODE[3:0] strap-in pins set to 0111. The KSZ9021RL/RN exits chip power down mode when a hardware reset is applied to the RESET_N pin with the MODE[3:0] strap-in pins set to an operating mode other than chip power down mode. Register Map The IEEE 802.3 Specification provides a 32 register address space for the PHY. Registers 0 thru 15 are standard PHY registers, defined per the specification. Registers 16 thru 31 are vendor specific registers. The KSZ9021RL/RN uses the IEEE provided register space for IEEE Defined Registers and Vendor Specific Registers, and uses the following registers to access Extended Registers: • Register 11 (Bh) for Extended Register – Control • Register 12 (Ch) for Extended Register – Data Write • Register 13 (Dh) for Extended Register – Data Read Examples: • Extended Register Read // Read from Operation Mode Strap Status Register 1. Write register 11 (Bh) with 0103h // Set register 259 (103h) for read 2. Read register 13 (Dh) // Read register value • Extended Register Write // Write to Operation Mode Strap Override Register 1. Write register 11 (Bh) with 8102h // Set register 258 (102h) for write 2. Write register 12 (Ch) with 0010h // Write 0010h value to register to set NAND Tree mode Register Number (Hex) Description IEEE Defined Registers 0 (0h) Basic Control 1 (1h) Basic Status 2 (2h) PHY Identifier 1 3 (3h) PHY Identifier 2 4 (4h) Auto-Negotiation Advertisement 5 (5h) Auto-Negotiation Link Partner Ability 6 (6h) Auto-Negotiation Expansion 7 (7h) Auto-Negotiation Next Page February 13, 2014 35 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Register Number (Hex) Description 8 (8h) Auto-Negotiation Link Partner Next Page Ability 9 (9h) 1000Base-T Control 10 (Ah) 1000Base-T Status 11 (Bh) Extended Register – Control 12 (Ch) Extended Register – Data Write 13 (Dh) Extended Register – Data Read 14 (Eh) Reserved 15 (Fh) Extended – MII Status Vendor Specific Registers 16 (10h) Reserved 17 (11h) Remote Loopback, LED Mode 18 (12h) LinkMD® – Cable Diagnostic 19 (13h) Digital PMA/PCS Status 20 (14h) Reserved 21 (15h) RXER Counter 22 (16h) – 26 (1Ah) Reserved 27 (1Bh) Interrupt Control/Status 28 (1Ch) Digital Debug Control 1 29 (1Dh) – 30 (1Eh) Reserved 31 (1Fh) PHY Control Extended Registers 256 (100h) Common Control 257 (101h) Strap Status 258 (102h) Operation Mode Strap Override 259 (103h) Operation Mode Strap Status 260 (104h) RGMII Clock and Control Pad Skew 261 (105h) RGMII RX Data Pad Skew 262 (106h) RGMII TX Data Pad Skew 263 (107h) Analog Test Register Register Description IEEE Defined Registers Address Name Description Mode(1) Default Register 0 (0h) – Basic Control 0.15 Reset 1 = Software PHY reset RW/SC 0 0 = Normal operation This bit is self-cleared after a ‘1’ is written to it. 0.14 Loop-back 1 = Loop-back mode RW 0 0 = Normal operation February 13, 2014 36 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Address Name Description Mode(1) Default 0.13 Speed Select [0.6, 0.13] RW Hardware Setting (LSB) [1,1] = Reserved [1,0] = 1000Mbps [0,1] = 100Mbps [0,0] = 10Mbps This bit is ignored if auto-negotiation is enabled (register 0.12 = 1). 0.12 Auto- 1 = Enable auto-negotiation process RW 1 Negotiation 0 = Disable auto-negotiation process Enable If enabled, auto-negotiation result overrides settings in register 0.13, 0.8 and 0.6. 0.11 Power Down 1 = Power down mode RW 0 0 = Normal operation 0.10 Isolate 1 = Electrical isolation of PHY from RGMII RW 0 0 = Normal operation 0.9 Restart Auto- 1 = Restart auto-negotiation process RW/SC 0 Negotiation 0 = Normal operation. This bit is self-cleared after a ‘1’ is written to it. 0.8 Duplex Mode 1 = Full-duplex RW Hardware Setting 0 = Half-duplex 0.7 Reserved RW 0 0.6 Speed Select [0.6, 0.13] RW 0 (MSB) [1,1] = Reserved [1,0] = 1000Mbps [0,1] = 100Mbps [0,0] = 10Mbps This bit is ignored if auto-negotiation is enabled (register 0.12 = 1). 0.5:0 Reserved RO 00_0000 Register 1 (1h) – Basic Status 1.15 100Base-T4 1 = T4 capable RO 0 0 = Not T4 capable 1.14 100Base-TX 1 = Capable of 100Mbps full-duplex RO 1 Full Duplex 0 = Not capable of 100Mbps full-duplex 1.13 100Base-TX 1 = Capable of 100Mbps half-duplex RO 1 Half Duplex 0 = Not capable of 100Mbps half-duplex 1.12 10Base-T Full 1 = Capable of 10Mbps full-duplex RO 1 Duplex 0 = Not capable of 10Mbps full-duplex 1.11 10Base-T Half 1 = Capable of 10Mbps half-duplex RO 1 Duplex 0 = Not capable of 10Mbps half-duplex 1.10:9 Reserved RO 00 1.8 Extended 1 = Extended Status Information in Reg. 15. RO 1 Status 0 = No Extended Status Information in Reg. 15. 1.7 Reserved RO 0 February 13, 2014 37 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Address Name Description Mode(1) Default 1.6 No Preamble 1 = Preamble suppression RO 1 0 = Normal preamble 1.5 Auto- 1 = Auto-negotiation process completed RO 0 Negotiation 0 = Auto-negotiation process not completed Complete 1.4 Remote Fault 1 = Remote fault RO/LH 0 0 = No remote fault 1.3 Auto- 1 = Capable to perform auto-negotiation RO 1 Negotiation 0 = Not capable to perform auto-negotiation Ability 1.2 Link Status 1 = Link is up RO/LL 0 0 = Link is down 1.1 Jabber Detect 1 = Jabber detected RO/LH 0 0 = Jabber not detected (default is low) 1.0 Extended 1 = Supports extended capabilities registers RO 1 Capability Register 2 (2h) – PHY Identifier 1 2.15:0 PHY ID Assigned to the 3rd through 18th bits of the RO 0022h Number Organizationally Unique Identifier (OUI). Kendin Communication’s OUI is 0010A1 (hex) Register 3 (3h) – PHY Identifier 2 3.15:10 PHY ID Assigned to the 19th through 24th bits of the RO 0001_01 Number Organizationally Unique Identifier (OUI). Kendin Communication’s OUI is 0010A1 (hex) 3.9:4 Model Number Six bit manufacturer’s model number RO 10_0001 3.3:0 Revision Four bit manufacturer’s revision number RO Indicates silicon revision Number Register 4 (4h) – Auto-Negotiation Advertisement 4.15 Next Page 1 = Next page capable RW 0 0 = No next page capability. 4.14 Reserved RO 0 4.13 Remote Fault 1 = Remote fault supported RW 0 0 = No remote fault 4.12 Reserved RO 0 4.11:10 Pause [4.11, 4.10] RW 00 [0,0] = No PAUSE [1,0] = Asymmetric PAUSE (link partner) [0,1] = Symmetric PAUSE [1,1] = Symmetric & Asymmetric PAUSE (local device) 4.9 100Base-T4 1 = T4 capable RO 0 0 = No T4 capability 4.8 100Base-TX 1 = 100Mbps full-duplex capable RW 1 Full-Duplex 0 = No 100Mbps full-duplex capability 4.7 100Base-TX 1 = 100Mbps half-duplex capable RW 1 Half-Duplex 0 = No 100Mbps half-duplex capability February 13, 2014 38 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Address Name Description Mode(1) Default 4.6 10Base-T 1 = 10Mbps full-duplex capable RW 1 Full-Duplex 0 = No 10Mbps full-duplex capability 4.5 10Base-T 1 = 10Mbps half-duplex capable RW 1 Half-Duplex 0 = No 10Mbps half-duplex capability 4.4:0 Selector Field [00001] = IEEE 802.3 RW 0_0001 Register 5 (5h) – Auto-Negotiation Link Partner Ability 5.15 Next Page 1 = Next page capable RO 0 0 = No next page capability 5.14 Acknowledge 1 = Link code word received from partner RO 0 0 = Link code word not yet received 5.13 Remote Fault 1 = Remote fault detected RO 0 0 = No remote fault 5.12 Reserved RO 0 5.11:10 Pause [5.11, 5.10] RW 00 [0,0] = No PAUSE [1,0] = Asymmetric PAUSE (link partner) [0,1] = Symmetric PAUSE [1,1] = Symmetric & Asymmetric PAUSE (local device) 5.9 100Base-T4 1 = T4 capable RO 0 0 = No T4 capability 5.8 100Base-TX 1 = 100Mbps full-duplex capable RO 0 Full-Duplex 0 = No 100Mbps full-duplex capability 5.7 100Base-TX 1 = 100Mbps half-duplex capable RO 0 Half-Duplex 0 = No 100Mbps half-duplex capability 5.6 10Base-T 1 = 10Mbps full-duplex capable RO 0 Full-Duplex 0 = No 10Mbps full-duplex capability 5.5 10Base-T 1 = 10Mbps half-duplex capable RO 0 Half-Duplex 0 = No 10Mbps half-duplex capability 5.4:0 Selector Field [00001] = IEEE 802.3 RO 0_0000 Register 6 (6h) – Auto-Negotiation Expansion 6.15:5 Reserved RO 0000_0000_000 6.4 Parallel 1 = Fault detected by parallel detection RO/LH 0 Detection Fault 0 = No fault detected by parallel detection. 6.3 Link Partner 1 = Link partner has next page capability RO 0 Next Page 0 = Link partner does not have next page Able capability 6.2 Next Page 1 = Local device has next page capability RO 1 Able 0 = Local device does not have next page capability 6.1 Page Received 1 = New page received RO/LH 0 0 = New page not received yet 6.0 Link Partner 1 = Link partner has auto-negotiation capability RO 0 Auto- 0 = Link partner does not have auto-negotiation Negotiation capability Able February 13, 2014 39 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Address Name Description Mode(1) Default Register 7 (7h) – Auto-Negotiation Next Page 7.15 Next Page 1 = Additional next page(s) will follow RW 0 0 = Last page 7.14 Reserved RO 0 7.13 Message Page 1 = Message page RW 1 0 = Unformatted page 7.12 Acknowledge2 1 = Will comply with message RW 0 0 = Cannot comply with message 7.11 Toggle 1 = Previous value of the transmitted link code RO 0 word equaled logic one 0 = Logic zero 7.10:0 Message Field 11-bit wide field to encode 2048 messages RW 000_0000_0001 Register 8 (8h) – Auto-Negotiation Link Partner Next Page Ability 8.15 Next Page 1 = Additional Next Page(s) will follow RO 0 0 = Last page 8.14 Acknowledge 1 = Successful receipt of link word RO 0 0 = No successful receipt of link word 8.13 Message Page 1 = Message page RO 0 0 = Unformatted page 8.12 Acknowledge2 1 = Able to act on the information RO 0 0 = Not able to act on the information 8.11 Toggle 1 = Previous value of transmitted link code RO 0 word equal to logic zero 0 = Previous value of transmitted link code word equal to logic one 8.10:0 Message Field RO 000_0000_0000 Register 9 (9h) – 1000Base-T Control 9:15:13 Test Mode Bits Transmitter test mode operations RW 000 [9.15:13] Mode [000] Normal Operation [001] Test mode 1 –Transmit waveform test [010] Test mode 2 –Transmit jitter test in Master mode [011] Test mode 3 –Transmit jitter test in Slave mode [100] Test mode 4 –Transmitter distortion test [101] Reserved, operations not identified [110] Reserved, operations not identified [111] Reserved, operations not identified February 13, 2014 40 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Address Name Description Mode(1) Default 9.12 MASTER- 1 = Enable MASTER-SLAVE Manual RW 0 SLAVE configuration value Manual Config 0 = Disable MASTER-SLAVE Manual Enable configuration value 9.11 MASTER- 1 = Configure PHY as MASTER during RW 0 SLAVE MASTER-SLAVE negotiation Manual Config 0 = Configure PHY as SLAVE during MASTER- Value SLAVE negotiation This bit is ignored if MASTER-SLAVE Manual Config is disabled (register 9.12 = 0). 9.10 Port Type 1 = Indicate the preference to operate as RW 0 multiport device (MASTER) 0 = Indicate the preference to operate as single- port device (SLAVE) This bit is valid only if the MASTER-SLAVE Manual Config Enable bit is disabled (register 9.12 = 0). 9.9 1000Base-T 1 = Advertise PHY is 1000Base-T full-duplex RW 1 Full-Duplex capable 0 = Advertise PHY is not 1000Base-T full- duplex capable 9.8 1000Base-T 1 = Advertise PHY is 1000Base-T half-duplex RW Hardware Setting Half-Duplex capable 0 = Advertise PHY is not 1000Base-T half- duplex capable 9.7:0 Reserved Write as 0, ignore on read RO Register 10 (Ah) – 1000Base-T Status 10.15 MASTER- 1 = MASTER-SLAVE configuration fault RO/LH/SC 0 SLAVE detected configuration 0 = No MASTER-SLAVE configuration fault fault detected 10.14 MASTER- 1 = Local PHY configuration resolved to RO 0 SLAVE MASTER configuration 0 = Local PHY configuration resolved to resolution SLAVE 10.13 Local 1 = Local Receiver OK (loc_rcvr_status = 1) RO 0 Receiver 0 = Local Receiver not OK (loc_rcvr_status = 0) Status 10.12 Remote 1 = Remote Receiver OK (rem_rcvr_status = 1) RO 0 Receiver 0 = Remote Receiver not OK (rem_rcvr_status Status = 0) 10.11 LP 1000T FD 1 = Link Partner is capable of 1000Base-T full- RO 0 duplex 0 = Link Partner is not capable of 1000Base-T full-duplex A.10 LP 1000T HD 1 = Link Partner is capable of 1000Base-T half- RO 0 duplex 0 = Link Partner is not capable of 1000Base-T half-duplex 10.9:8 Reserved RO 00 February 13, 2014 41 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Address Name Description Mode(1) Default 10.7:0 Idle Error Cumulative count of errors detected when RO/SC 0000_0000 Count receiver is receiving idles and PMA_TXMODE.indicate = SEND_N. The counter is incremented every symbol period that rxerror_status = ERROR. Register 11 (Bh) – Extended Register – Control 11.15 Extended 1 = Write Extended Register RW 0 Register – 0 = Read Extended Register read/write select 11.14:9 Reserved RW 000_000 11.8 Extended Select page for Extended Register RW 0 Register – page 11.7:0 Extended Select Extended Register Address RW 0000_0000 Register – address Register 12 (Ch) – Extended Register – Data Write 12.15:0 Extended 16-bit value to write to Extend Register Address RW 0000_0000_0000_0000 Register – in register 11 (Bh) bits [7:0] write Register 13 (Dh) – Extended Register – Data Read 13.15:0 Extended 16-bit value read from Extend Register Address RO 0000_0000_0000_0000 Register – in register 11 (Bh) bits [7:0] read Register 15 (Fh) – Extended – MII Status 15.15 1000Base-X 1 = PHY able to perform 1000Base-X RO 0 Full-duplex full-duplex 0 = PHY not able to perform 1000Base-X full-duplex 15.14 1000Base-X 1 = PHY able to perform 1000Base-X RO 0 Half-duplex half-duplex 0 = PHY not able to perform 1000Base-X half-duplex 15.13 1000Base-T 1 = PHY able to perform 1000Base-T RO 1 Full-duplex full-duplex 1000BASE-X 0 = PHY not able to perform 1000Base-T full-duplex 15.12 1000Base-T 1 = PHY able to perform 1000Base-T RO 1 Half-duplex half-duplex 0 = PHY not able to perform 1000Base-T half-duplex 15.11:0 Reserved Ignore when read RO - Note: 1. RW = Read/Write. RO = Read only. SC = Self-cleared. LH = Latch high. LL = Latch low. February 13, 2014 42 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Vendor Specific Registers Address Name Description Mode(1) Default Register 17 (11h) – Remote Loopback, LED Mode 17.15:9 Reserved RW 0000_001 17.8 Remote 1 = Enable Remote Loopback RW 0 Loopback 0 = Disable Remote Loopback 17.7:6 Reserved RW 11 17.5:4 Reserved RW 11 17.3 LED Test 1 = Enable LED test mode RW 0 Enable 0 = Disable LED test mode 17.2:1 Reserved RW 00 17.0 Reserved RO 0 Register 18 (12h) – LinkMD® – Cable Diagnostic 18.15 Reserved RW/SC 0 18.14:8 Reserved RW 000_0000 18.7:0 Reserved RO 0000_0000 Register 19 (13h) – Digital PMA/PCS Status 19.15:3 Reserved RO/LH 0000_0000_0000_0 19.2 1000Base-T 1000 Base-T Link Status RO 0 Link Status 1 = Link status is OK 0 = Link status is not OK 19.1 100Base-TX 100 Base-TX Link Status RO 0 Link Status 1 = Link status is OK 0 = Link status is not OK 19.0 Reserved RO 0 Register 21 (15h) – RXER Counter 21.15:0 RXER Counter Receive error counter for Symbol Error frames RO/RC 0000_0000_0000_0000 Register 27 (1Bh) – Interrupt Control/Status 27.15 Jabber 1 = Enable Jabber Interrupt RW 0 Interrupt 0 = Disable Jabber Interrupt Enable 27.14 Receive Error 1 = Enable Receive Error Interrupt RW 0 Interrupt 0 = Disable Receive Error Interrupt Enable 27.13 Page Received 1 = Enable Page Received Interrupt RW 0 Interrupt 0 = Disable Page Received Interrupt Enable 27.12 Parallel Detect 1 = Enable Parallel Detect Fault Interrupt RW 0 Fault Interrupt 0 = Disable Parallel Detect Fault Interrupt Enable 27.11 Link Partner 1 = Enable Link Partner Acknowledge Interrupt RW 0 Acknowledge 0 = Disable Link Partner Acknowledge Interrupt Interrupt Enable 27.10 Link Down 1 = Enable Link Down Interrupt RW 0 Interrupt 0 = Disable Link Down Interrupt Enable February 13, 2014 43 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Address Name Description Mode(1) Default 27.9 Remote Fault 1 = Enable Remote Fault Interrupt RW 0 Interrupt 0 = Disable Remote Fault Interrupt Enable 27.8 Link Up 1 = Enable Link Up Interrupt RW 0 Interrupt 0 = Disable Link Up Interrupt Enable 27.7 Jabber 1 = Jabber occurred RO/RC 0 Interrupt 0 = Jabber did not occurred 27.6 Receive Error 1 = Receive Error occurred RO/RC 0 Interrupt 0 = Receive Error did not occurred 27.5 Page Receive 1 = Page Receive occurred RO/RC 0 Interrupt 0 = Page Receive did not occurred 27.4 Parallel Detect 1 = Parallel Detect Fault occurred RO/RC 0 Fault Interrupt 0 = Parallel Detect Fault did not occurred 27.3 Link Partner 1 = Link Partner Acknowledge occurred RO/RC 0 Acknowledge 0 = Link Partner Acknowledge did not occurred Interrupt 27.2 Link Down 1 = Link Down occurred RO/RC 0 Interrupt 0 = Link Down did not occurred 27.1 Remote Fault 1 = Remote Fault occurred RO/RC 0 Interrupt 0 = Remote Fault did not occurred 27.0 Link Up 1 = Link Up occurred RO/RC 0 Interrupt 0 = Link Up did not occurred Register 28 (1Ch) – Digital Debug Control 1 28.15:8 Reserved RW 0000_0000 28.7 mdi_set mdi_set has no function when swapoff (reg28.6) RW 0 is de-asserted. 1 = When swapoff is asserted, if mdi_set is asserted, chip will operate at MDI mode. 0 = When swapoff is asserted, if mdi_set is de- asserted, chip will operate at MDI-X mode. 28.6 swapoff 1 = Disable auto crossover function RW 0 0 = Enable auto crossover function 28.5:1 Reserved RW 00_000 28.0 PCS Loopback 1 = Enable 10Base-T and 100Base-TX RW 0 Loopback for register 0h bit 14. 0 = normal function Register 31 (1Fh) – PHY Control 31.15 Reserved RW 0 31.14 Interrupt Level 1 = Interrupt pin active high RW 0 0 = Interrupt pin active low 31.13:12 Reserved RW 00 31.11:10 Reserved RO/LH/RC 00 31.9 Enable Jabber 1 = Enable jabber counter RW 1 0 = Disable jabber counter 31.8:7 Reserved RW 00 February 13, 2014 44 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Address Name Description Mode(1) Default 31.6 Speed status 1 = Indicate chip final speed status at RO 0 1000Base-T 1000Base-T 31.5 Speed status 1 = Indicate chip final speed status at RO 0 100Base-TX 100Base-TX 31.4 Speed status 1 = Indicate chip final speed status at RO 0 10Base-T 10Base-T 31.3 Duplex status Indicate chip duplex status RO 0 1 = Full-duplex 0 = Half-duplex 31.2 1000Base-T 1 = Indicate 1000Base-T Master mode RO 0 Mater/Slave 0 = Indicate 1000Base-T Slave mode status 31.1 Software 1 = Reset chip, except all registers RW 0 Reset 0 = Disable reset 31.0 Link Status 1 = Fail RO 0 Check Fail 0 = Not Failing Note: 1. RW = Read/Write. RC = Read-cleared RO = Read only. SC = Self-cleared. LH = Latch high. Extended Registers Address Name Description Mode(1) Default Register 256 (100h) – Common Control 256.15:9 Reserved RW 0000_000 256.8 RGMII In-band 1 = Enable RW 0 PHY Status 0 = Disable 256.7:0 Reserved RW Register 257 (101h) – Strap Status 257.15:6 Reserved RO 257.5 CLK125_EN 1 = CLK125_EN strap-in is enabled RO status 0 = CLK125_EN strap-in is disabled 257.4:0 PHYAD[4:0] Strapped-in value for PHY Address RO status Register 258 (102h) – Operation Mode Strap Override 258.15 RGMII all 1 = Override strap-in for RGMII advertise all RW capabilities capabilities override 258.14 RGMII no 1 = Override strap-in for RGMII advertise all RW 1000BT_HD capabilities except 1000Base-T half-duplex override 258.13 RGMII 1 = Override strap-in for RGMII advertise RW 1000BT_H/FD 1000Base-T full and half-duplex only only override February 13, 2014 45 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Address Name Description Mode(1) Default 258.12 RGMII 1 = Override strap-in for RGMII advertise RW 1000BT_FD 1000Base-T full-duplex only only override 258.11:8 Reserved RW 258.7 Tri-state all 1 = Tri-state all digital I/Os for further power RW 0 digital I/Os saving during software power down 258.6:5 Reserved RW 258.4 NAND Tree 1 = Override strap-in for NAND Tree mode RW override 258.3:0 Reserved RW Register 259 (103h) – Operation Mode Strap Status 259.15 RGMII all 1 = Strap to RGMII advertise all capabilities RO capabilities strap-in status 259.14 RGMII no 1 = Strap to RGMII advertise all capabilities RO 1000BT_HD except 1000Base-T half-duplex strap-in status 259.13 RGMII only 1 = Strap to RGMII advertise 1000Base-T full RO 1000BT_H/FD and half-duplex only strap-in status 259.12 RGMII only 1 = Strap to RGMII advertise 1000Base-T full- RO 1000BT_FD duplex only strap-in status 259.11:5 Reserved RO 259.4 NAND Tree 1 = Strap to NAND Tree mode RO strap-in status 259.3:0 Reserved RO Register 260 (104h) – RGMII Clock and Control Pad Skew 260.15:12 rxc_pad_skew RGMII RXC PAD Skew Control (0.12ns/step) RW 0111 260.11:8 rxdv_pad_skew RGMII RX_CTL PAD Skew Control RW 0111 (0.12ns/step) 260.7:4 txc_pad_skew RGMII TXC PAD Skew Control (0.12ns/step) RW 0111 260.3:0 txen_pad_skew RGMII TX_CTL PAD Skew Control RW 0111 (0.12ns/step) Register 261 (105h) – RGMII RX Data Pad Skew 261.15:12 rxd3_pad_skew RGMII RXD3 PAD Skew Control (0.12ns/step) RW 0111 261.11:8 rxd2_pad_skew RGMII RXD2 PAD Skew Control (0.12ns/step) RW 0111 261.7:4 rxd1_pad_skew RGMII RXD1 PAD Skew Control (0.12ns/step) RW 0111 261.3:0 rxd0_pad_skew RGMII RXD0 PAD Skew Control (0.12ns/step) RW 0111 Register 262 (106h) – RGMII TX Data Pad Skew 262.15:12 txd3_pad_skew RGMII TXD3 PAD Skew Control (0.12ns/step) RW 0111 262.11:8 txd2_pad_skew RGMII TXD2 PAD Skew Control (0.12ns/step) RW 0111 262.7:4 txd1_pad_skew RGMII TXD1 PAD Skew Control (0.12ns/step) RW 0111 262.3:0 txd0_pad_skew RGMII TXD0 PAD Skew Control (0.12ns/step) RW 0111 February 13, 2014 46 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Address Name Description Mode(1) Default Register 263 (107h) – Analog Test Register 263.15 LDO disable 1 = LDO controller disable RW 0 0 = LDO controller enable 263.14:9 Reserved RW 000_000 263.8 Low frequency 1 = Low frequency oscillator mode enable RW 0 oscillator mode 0 = Low frequency oscillator mode disable Use for further power saving during software power down. 263.7:0 Reserved RW 0000_0000 Note: 1. RW = Read/Write. RO = Read only. February 13, 2014 47 Revision 1.2

Micrel, Inc. KSZ9021RL/RN (1) (2) Absolute Maximum Ratings Operating Ratings Supply Voltage Supply Voltage (DVDDL, AVDDL, AVDDL_PLL) ............ –0.5V to +1.8V (DVDDL, AVDDL, AVDDL_PLL).... +1.140V to +1.260V (AVDDH) ................................................ –0.5V to +5.0V (AVDDH) ........................................ +3.135V to +3.465V (DVDDH) ................................................ –0.5V to +5.0V (DVDDH @ 3.3V) .......................... +3.135V to +3.465V Input Voltage (all inputs) .............................. –0.5V to +5.0V (DVDDH @ 2.5V) .......................... +2.375V to +2.625V Output Voltage (all outputs) ......................... –0.5V to +5.0V Ambient Temperature Lead Temperature (soldering, 10s) ............................ 260°C (T Commercial: KSZ9021RL/RN) .......... 0°C to +70°C A Storage Temperature (T ) ......................... –55°C to +150°C (T Industrial: KSZ9021RLI/RNI) ......... –40°C to +85°C s A Maximum Junction Temperature (T Max) ................. 125°C J Thermal Resistance (θ ) .................................... 31.85°C/W JA Thermal Resistance (θ ) ...................................... 8.07°C/W JC (3) Electrical Characteristics Symbol Parameter Condition Min Typ Max Units Supply Current – Core / Digital I/Os ICORE 1.2V total of: 1000Base-T Link-up (no traffic) 528 mA DVDDL (1.2V digital core) + 1000Base-T Full-duplex @ 100% utilization 563 mA AVDDL (1.2V analog core) + 100Base-TX Link-up (no traffic) 158 mA AVDDL_PLL (1.2V for PLL) 100Base-TX Full-duplex @ 100% utilization 158 mA 10Base-T Link-up (no traffic) 7 mA 10Base-T Full-duplex @ 100% utilization 7 mA Power Saving Mode (cable unplugged) 15 mA Software Power Down Mode (register 0.11 =1) 1.3 mA Chip Power Down Mode 1.3 mA (strap-in pins MODE[3:0] = 0111) IDVDDH_2.5 2.5V for digital I/Os 1000Base-T Link-up (no traffic) 13 mA 1000Base-T Full-duplex @ 100% utilization 37 mA (RGMII operating @ 2.5V) 100Base-TX Link-up (no traffic) 4 mA 100Base-TX Full-duplex @ 100% utilization 9 mA 10Base-T Link-up (no traffic) 2 mA 10Base-T Full-duplex @ 100% utilization 5 mA Power Saving Mode (cable unplugged) 7 mA Software Power Down Mode (register 0.11 =1) 3 mA Chip Power Down Mode 1 mA (strap-in pins MODE[3:0] = 0111) IDVDDH_3.3 3.3V for digital I/Os 1000Base-T Link-up (no traffic) 20 mA 1000Base-T Full-duplex @ 100% utilization 58 mA (RGMII operating @ 3.3V) 100Base-TX Link-up (no traffic) 11 mA 100Base-TX Full-duplex @ 100% utilization 15 mA 10Base-T Link-up (no traffic) 5 mA 10Base-T Full-duplex @ 100% utilization 11 mA Power Saving Mode (cable unplugged) 9 mA Software Power Down Mode (register 0.11 =1) 7 mA Chip Power Down Mode 1 mA (strap-in pins MODE[3:0] = 0111) February 13, 2014 48 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Symbol Parameter Condition Min Typ Max Units Supply Current – Transceiver (equivalent to current draw through external transformer center taps for PHY transceivers with current-mode transmit drivers) IAVDDH 3.3V for transceiver 1000Base-T Link-up (no traffic) 75 mA 1000Base-T Full-duplex @ 100% utilization 75 mA 100Base-TX Link-up (no traffic) 29 mA 100Base-TX Full-duplex @ 100% utilization 29 mA 10Base-T Link-up (no traffic) 35 mA 10Base-T Full-duplex @ 100% utilization 43 mA Power Saving Mode (cable unplugged) 36 mA Software Power Down Mode (register 0.11 =1) 2 mA Chip Power Down Mode 1 mA (strap-in pins MODE[3:0] = 0111) TTL Inputs VIH Input High Voltage 2.0 V VIL Input Low Voltage 0.8 V IIN Input Current VIN = GND ~ VDDIO –10 10 µA TTL Outputs VOH Output High Voltage IOH = –4mA 2.4 V VOL Output Low Voltage IOL = 4mA 0.4 V |Ioz| Output Tri-State Leakage 10 µA 100Base-TX Transmit (measured differentially after 1:1 transformer) VO Peak Differential Output Voltage 100Ω termination across differential output 0.95 1.05 V VIMB Output Voltage Imbalance 100Ω termination across differential output 2 % tr, tf Rise/Fall Time 3 5 ns Rise/Fall Time Imbalance 0 0.5 ns Duty Cycle Distortion ± 0.25 ns Overshoot 5 % VSET Reference Voltage of ISET R(ISET) = 4.99k 0.535 V Output Jitter Peak-to-peak 0.7 1.4 ns 10Base-T Transmit (measured differentially after 1:1 transformer) VP Peak Differential Output Voltage 100Ω termination across differential output 2.2 2.8 V Jitter Added Peak-to-peak 3.5 ns Harmonic Rejection Transmit all-one signal sequence –31 dB 10Base-T Receive VSQ Squelch Threshold 5MHz square wave 300 400 mV Notes: 1. Exceeding the absolute maximum rating may damage the device. Stresses greater than the absolute maximum rating may cause permanent damage to the device. Operation of the device at these or any other conditions above those specified in the operating sections of this specification is not implied. Maximum conditions for extended periods may affect reliability. 2. The device is not guaranteed to function outside its operating rating. 3. TA = 25°C. Specification is for packaged product only. February 13, 2014 49 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Timing Diagrams RGMII Timing The KSZ9021RL/RN RGMII timing conforms to the timing requirements per the RGMII Version 1.3 Specification. Figure 5. RGMII v1.3 Specification (Figure 2 – Multiplexing and Timing Diagram) Timing Parameter Description Min Typ Max Unit TskewT Data to Clock output Skew (at Transmitter) –500 500 ps TskewR Data to Clock input Skew (at Receiver) 1 2.6 ns Tcyc (1000Base-T) Clock Cycle Duration for 1000Base-T 7.2 8 8.8 ns Tcyc (100Base-TX) Clock Cycle Duration for 100Base-TX 36 40 44 ns Tcyc (10Base-T) Clock Cycle Duration for 10Base-T 360 400 440 ns Table 12. RGMII v1.3 Specification (Timing Specifics from Table 2) Accounting for TskewT, the TskewR specification in the above table requires the PCB board design to incorporate clock routing for TXC and RXC with an additional trace delay of greater than 1.5ns and less than 2.1ns for 1000Base-T. For 10Base-T/100Base-TX, the maximum delay is much greater than the 2.1ns for 1000Base-T, and thus is not specified. Alternatively, the KSZ9021RL/RN can be programmed to support RGMII v2.0 with the required data-to-clock skew implemented on-chip. If the delay is not implemented on the PCB and not programmed inside the MAC, the clock skew delay can be implemented via KSZ9021RL/RN registers 260 (104h), 261 (105h) and 262 (106h). See RGMII Pad Skew Registers section. February 13, 2014 50 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Auto-Negotiation Timing Auto-Negotiation Fast Link Pulse (FLP) Timing FLP FLP Burst Burst TX+/TX- t FLPW t BTB Clock Data Clock Data Pulse Pulse Pulse Pulse TX+/TX- t t PW PW t CTD t CTC Figure 6. Auto-Negotiation Fast Link Pulse (FLP) Timing Timing Parameter Description Min Typ Max Units tBTB FLP Burst to FLP Burst 8 16 24 ms tFLPW FLP Burst width 2 ms tPW Clock/Data Pulse width 100 ns tCTD Clock Pulse to Data Pulse 55.5 64 69.5 µs tCTC Clock Pulse to Clock Pulse 111 128 139 µs Number of Clock/Data Pulse per 17 33 FLP Burst Table 13. Auto-Negotiation Fast Link Pulse (FLP) Timing Parameters February 13, 2014 51 Revision 1.2

Micrel, Inc. KSZ9021RL/RN MDC/MDIO Timing t P MDC t t MD1 MD2 MDIO Valid Valid (PHY input) Data Data t MD3 MDIO Valid (PHY output) Data Figure 7. MDC/MDIO Timing Timing Parameter Description Min Typ Max Unit tP MDC period 400 ns t1MD1 MDIO (PHY input) setup to rising edge of MDC 10 ns tMD2 MDIO (PHY input) hold from rising edge of MDC 10 ns tMD3 MDIO (PHY output) delay from rising edge of MDC 0 ns Table 14. MDC/MDIO Timing Parameters February 13, 2014 52 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Reset Timing The recommended KSZ9021RL/RN power-up reset timing is summarized in the following figure and table. Supply Voltage tsr RESET_N Figure 8. Reset Timing Parameter Description Min Max Units tsr Stable supply voltage to reset high 10 ms Table 15. Reset Timing Parameters After the de-assertion of reset, it is recommended to wait a minimum of 100µs before starting programming on the MIIM (MDC/MDIO) Interface. Reset Circuit The following reset circuit is recommended for powering up the KSZ9021RL/RN if reset is triggered by the power supply. DVDDH D1: 1N4148 D1 R 10K KSZ9021RL/RN RESET_N C 10uF Figure 9. Recommended Reset Circuit February 13, 2014 53 Revision 1.2

Micrel, Inc. KSZ9021RL/RN The following reset circuit is recommended for applications where reset is driven by another device (e.g., CPU or FPGA). At power-on-reset, R, C and D1 provide the necessary ramp rise time to reset the KSZ9021RL/RN device. The RST_OUT_n from CPU/FPGA provides the warm reset after power up. DVDDH R 10K D1 KSZ9021RL/RN CPU/FPGA RESET_N RST_OUT_n D2 C 10uF D1, D2: 1N4148 Figure 10. Recommended Reset Circuit for Interfacing with CPU/FPGA Reset Output Reference Circuits – LED Strap-in Pins The pull-up and pull-down reference circuits for the LED2/PHYAD1 and LED1/PHYAD0 strapping pins are shown in the following figure. DVDDH Pull-up 10ΚΩ 220Ω KSZ9021RL/RN LED pin DVDDH Pull-down 220Ω KSZ9021RL/RN LED pin 1ΚΩ Figure 11. Reference Circuits for LED Strapping Pins February 13, 2014 54 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Reference Clock – Connection and Selection A crystal or external clock source, such as an oscillator, is used to provide the reference clock for the KSZ9021RL/RN. The reference clock is 25 MHz for all operating modes of the KSZ9021RL/RN. The following figure and table show the reference clock connection to pins XI and XO of the KSZ9021RL/RN, and the reference clock selection criteria. 22pF 22pF XI XI 25MHz OSC 22pF +/-50ppm 22pF XO NC XO NC 25MHz XTAL +/-50ppm Figure 12. 25MHz Crystal/Oscillator Reference Clock Connection Characteristics Value Units Frequency 25 MHz Frequency tolerance (max) ±50 ppm Table 16. Reference Crystal/Clock Selection Criteria Magnetics Specification A 1:1 isolation transformer is required at the line interface. An isolation transformer with integrated common-mode chokes is recommended for exceeding FCC requirements. The following tables provide recommended magnetic characteristics and a list of qualified magnetics for the KSZ9021RL/RN. Parameter Value Test Condition Turns ratio 1 CT : 1 CT Open-circuit inductance (min.) 350µH 100mV, 100kHz, 8mA Insertion loss (max.) 1.0dB 0MHz–100MHz HIPOT (min.) 1500Vrms Table 17. Magnetics Selection Criteria Magnetic Manufacturer Part Number Auto MDI-X Number of Port Pulse H5007NL Yes 1 TDK TLA-7T101LF Yes 1 Table 18. Qualified Single Port 10/100/1000 Magnetics February 13, 2014 55 Revision 1.2

Micrel, Inc. KSZ9021RL/RN Package Information 48-Pin (7mm x 7mm) QFN February 13, 2014 56 Revision 1.2

Micrel, Inc. KSZ9021RL/RN 64-Pin (10mm x 10mm) E-LQFP (V) February 13, 2014 57 Revision 1.2

Micrel, Inc. KSZ9021RL/RN MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry, specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2009 Micrel, Incorporated. February 13, 2014 58 Revision 1.2