Micrel, Inc.
KSZ9021RL/RN
Mode(1)
Address
Name
Description
Default
0.13
Speed Select
(LSB)
[0.6, 0.13]
RW
Hardware Setting
[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
0.11
Auto-
Negotiation
Enable
1 = Enable auto-negotiation process
0 = Disable auto-negotiation process
RW
RW
1
0
If enabled, auto-negotiation result overrides
settings in register 0.13, 0.8 and 0.6.
Power Down
Isolate
1 = Power down mode
0 = Normal operation
0.10
0.9
1 = Electrical isolation of PHY from RGMII
0 = Normal operation
RW
0
0
Restart Auto-
Negotiation
1 = Restart auto-negotiation process
0 = Normal operation.
RW/SC
This bit is self-cleared after a ‘1’ is written to it.
1 = Full-duplex
0.8
Duplex Mode
Reserved
RW
Hardware Setting
0 = Half-duplex
0.7
0.6
RW
RW
0
0
Speed Select
(MSB)
[0.6, 0.13]
[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
RO
RO
RO
RO
RO
00_0000
Register 1 (1h) – Basic Status
1.15
1.14
1.13
1.12
1.11
100Base-T4
1 = T4 capable
0
1
1
1
1
0 = Not T4 capable
100Base-TX
Full Duplex
1 = Capable of 100Mbps full-duplex
0 = Not capable of 100Mbps full-duplex
1 = Capable of 100Mbps half-duplex
0 = Not capable of 100Mbps half-duplex
1 = Capable of 10Mbps full-duplex
0 = Not capable of 10Mbps full-duplex
100Base-TX
Half Duplex
10Base-T Full
Duplex
10Base-T Half 1 = Capable of 10Mbps half-duplex
Duplex
0 = Not capable of 10Mbps half-duplex
1.10:9
1.8
Reserved
RO
RO
00
1
Extended
Status
1 = Extended Status Information in Reg. 15.
0 = No Extended Status Information in Reg. 15.
M9999-101309-1.1
October 2009
35
MICREL [ MICREL SEMICONDUCTOR ]
