Micrel, Inc.

KSZ8041NL/RNL

September 2010

5

M9999-090910-1.4

Reduced MII (RMII) Data Interface................................................................................................................................... 25

RMII Signal Definition ....................................................................................................................................................... 26

Reference Clock (REF_CLK) ....................................................................................................................................... 26

Transmit Enable (TX_EN) ............................................................................................................................................ 26

Transmit Data [1:0] (TXD[1:0]) ..................................................................................................................................... 26

Carrier Sense/Receive Data Valid (CRS_DV).............................................................................................................. 27

Receive Data [1:0] (RXD[1:0]) ...................................................................................................................................... 27

Receive Error (RX_ER) ................................................................................................................................................ 27

Collision Detection........................................................................................................................................................ 27

RMII Signal Diagram......................................................................................................................................................... 27

HP Auto MDI/MDI-X.......................................................................................................................................................... 28

Straight Cable ............................................................................................................................................................... 29

Crossover Cable ........................................................................................................................................................... 29

Power Management.......................................................................................................................................................... 30

Power Saving Mode ..................................................................................................................................................... 30

Power Down Mode ....................................................................................................................................................... 30

Reference Clock Connection Options .............................................................................................................................. 30

Reference Circuit for Power and Ground Connections .................................................................................................... 31

Register Map........................................................................................................................................................................ 32

Register Description ........................................................................................................................................................... 32

Register Description (continued) ...................................................................................................................................... 33

Register Description (continued) ...................................................................................................................................... 34

Register Description (continued) ...................................................................................................................................... 35

Register Description (continued) ...................................................................................................................................... 36

Register Description (continued) ...................................................................................................................................... 37

Register Description (continued) ...................................................................................................................................... 38

Register Description (continued) ...................................................................................................................................... 39

Absolute Maximum Ratings

(1) ............................................................................................................................................ 40

Operating Ratings

(2) ............................................................................................................................................................ 40

Electrical Characteristics

(4) ................................................................................................................................................ 40

Electrical Characteristics

(4) (continued)............................................................................................................................ 41

Timing Diagrams ................................................................................................................................................................. 42

MII SQE Timing (10Base-T) ............................................................................................................................................. 42

MII Transmit Timing (10Base-T) ....................................................................................................................................... 43

MII Receive Timing (10Base-T) ........................................................................................................................................ 44

MII Transmit Timing (100Base-TX) .................................................................................................................................. 45

MII Receive Timing (100Base-TX) ................................................................................................................................... 46

RMII Timing....................................................................................................................................................................... 47

Auto-Negotiation Timing ................................................................................................................................................... 48

MDC/MDIO Timing ........................................................................................................................................................... 49

Reset Timing..................................................................................................................................................................... 50