Data Sheet

Programming Interface — Ethernet Controller I210
571
8.27.3.27 MAC Specific Control Register 2 - Page 2, Register 21
Bits Field Mode HW Rst SW Rst Description
15 Reserved R/W 0x0 0x0 Reserved.
14
Copper Line
Loopback
R/W 0x0 0x0
1b = Enable loopback of MDI-to-MDI.
0b = Normal operation.
13:12 Reserved R/W 0x1 Update Reserved.
11:7 Reserved R/W 0x0 0x0 Reserved.
6 Reserved R/W 0x1 Update Reserved.
5:4 Reserved R/W 0x0 Retain Reserved.
3
Block Carrier
Extension Bit
R/W 0x0 Retain
1b = Enable block carrier extension.
0b = Disable block carrier extension.
2:0
Default MAC
Interface Speed
R/W 0x6 Update
Changes to these bits are disruptive to the normal operation. As a
result, any changes to these registers must be followed by
software reset to take effect.
MAC interface speed during link down while auto-negotiation is
enabled.
Bit speed:
0XXb = Reserved.
100b = 10 Mb/s.
101b = 100 Mb/s.
110b = 1000 Mb/s.
111b = Reserved.