Micrel, Inc.
KSZ8041NL/RNL
Register Map
Register Number (Hex)
Description
0h
Basic Control
1h
Basic Status
2h
PHY Identifier 1
3h
PHY Identifier 2
4h
Auto-Negotiation Advertisement
Auto-Negotiation Link Partner Ability
Auto-Negotiation Expansion
Auto-Negotiation Next Page
Link Partner Next Page Ability
Reserved
5h
6h
7h
8h
9h – 13h
14h
MII Control
15h
RXER Counter
16h – 1Ah
1Bh
1Ch – 1Dh
1Eh
1Fh
Reserved
Interrupt Control/Status
Reserved
PHY Control 1
PHY Control 2
Register Description
Mode(1)
Address
Name
Description
Default
Register 0h – Basic Control
0.15
Reset
1 = Software reset
RW/SC
0
0 = Normal operation
This bit is self-cleared after a ‘1’ is written to it.
1 = Loop-back mode
0 = Normal operation
1 = 100Mbps
0.14
0.13
Loop-back
RW
RW
0
Speed Select
(LSB)
Set by SPEED strapping pin.
0 = 10Mbps
See “Strapping Options” section
for details.
This bit is ignored if auto-negotiation is enabled
(register 0.12 = 1).
0.12
Auto-
Negotiation
Enable
1 = Enable auto-negotiation process
0 = Disable auto-negotiation process
RW
Set by NWAYEN strapping pin.
See “Strapping Options” section
for details.
If enabled, auto-negotiation result overrides
settings in register 0.13 and 0.8.
0.11
0.10
Power Down
Isolate
1 = Power down mode
0 = Normal operation
RW
RW
0
1 = Electrical isolation of PHY from MII and
TX+/TX-
Set by ISO strapping pin.
See “Strapping Options” section
for details.
0 = Normal operation
September 2010
32
M9999-090910-1.4
MICREL [ MICREL SEMICONDUCTOR ]
