SMSC LAN9420i Manual De Usuario

Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface

SMSC LAN9420/LAN9420i

145

Revision 1.22 (09-25-08)

Index (In Decimal):

27

Size:

16 bits

15

Override AUTOMDIX_EN Strap
0 = AUTOMDIX_EN configuration strap enables or disables HP Auto MDIX.
1 = Override AUTOMDIX_EN configuration strap. PHY Register 27.14 and 

27.13 determine MDIX function.

R/W

0b

14

Auto-MDIX Enable
Only effective when 27.15=1, otherwise ignored.
0 = Disable Auto-MDIX. 27.13 determines normal or reversed connection.
1 = Enable Auto-MDIX. 27.13 must be set to 0.

R/W

0b

13

Auto-MDIX State
Only effective when 27.15=1, otherwise ignored.
When 27.14 = 0 (manually set MDIX state):

0 = no crossover (TPO = output, TPI = input)
1 = crossover (TPO = input, TPI = output)

When 27.14 = 1 (automatic MDIX) this bit must be set to 0.
Do not use the combination 27.15=1, 27.14=1, 27.13=1.

R/W

0b

12:11

RO

-

10

VCOOFF_LP
Forces the Receive PLL 10M to lock on the reference clock at all times: 0 
– Receive PLL 10M can lock on reference or line as needed (normal 
operation) 1 - Receive PLL 10M is locked on the reference clock. In this 
mode 10M data packets cannot be received.

R/W,

NASR

0b

9:5

RO

-

4

XPOL
Polarity state of the 10BASE-T:
0 – Normal polarity
1 – Reversed polarity

RO

0b

3:0

RO

-