Intel® IXP42X product line and IXC1100 control plane processors—Ethernet MAC A
Intel® IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
434 Order Number: 252480-006US
15.2.14 MDIO Commands Registers

Four registers make up the 32-bit MDIO Command that services both MII interfaces:

MDIO Command[31:24] — MDIO Command 4

MDIO Command[23:16] — MDIO Command 3

MDIO Command[15:8] — MDIO Command 2

MDIO Command[7:0] — MDIO Command 1

The detailed bit descriptions follow the four commands’ bit maps.

15.2.15 MDIO Command 115.2.16 MDIO Command 2
Register slottime
Bits Name Description
31:8 (Reserved)
7:0 Slot Time
Slot time for back-off algorithm
Expressed in number of tx_clk cycles.
128 in MII mode.
Register Name: mdiocmd1
Hex Offset Address: 0xC8009080 Reset Hex Value: 0x00000000
Register
Description: MDIO Command 1 (8 Bits of 32-Bit Register).
Access: Read/Write.
70
MDIO Command [7:0]
Register Name: mdiocmd2
Hex Offset Address: 0x C8009084 Reset Hex Value: 0x00000000
Register
Description: MDIO Command Register
Access: Read/Write.
31 87 0
(Reserved) MDIO_COMMAND [15:8]