SMSC LAN9420 - Manual (Page 136)

Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface
Datasheet
Revision 1.22 (09-25-08) 136 SMSC LAN9420/LAN9420i
DATASHEET
4.5.1 Basic Control Register
Index (In Decimal): 0 Size: 16 bits
BITS DESCRIPTION TYPE DEFAULT
15 PHY Soft Reset
1 = PHY software reset. Bit is self-clearing. When setting this bit do not set
other bits in this register. R/W/SC 0b
14 Loopback
1 = loopback mode, 0 = normal operation R/W 0b
13 Speed Select
1 = 100Mbps, 0 = 10Mbps. Ignored if Auto Negotiation is enabled (0.12 =
1). R/W 1b
12 Auto-Negotiation Enable
1 = enable auto-negotiate process (overrides 0.13 and 0.8) 0 = disable
auto-negotiate process. R/W 1b
11 Power Down
1 = General Power-Down mode, 0 = normal operation
Note: For maximum power savings, auto-negotiation should be disabled
before enabling the General Power-Down mode.
R/W 0b
10 RESERVED RO -
9 Restart Auto-Negotiate
1 = restart auto-negotiate process 0 = normal operation. Bit is self-clearing. R/W/SC 0b
8 Duplex Mode
1 = full duplex, 0 = half duplex. Ignored if Auto Negotiation is enabled (0.12
= 1). R/W 0b
7 Collision Test
1 = enable COL test, 0 = disable COL test R/W 0b
6:0 RESERVED RO -