Datasheet

16-bit Non-PCI Small Form Factor 10/100 Ethernet Controller with Variable Voltage I/O & HP Auto-MDIX Support
Datasheet
Revision 2.9 (03-01-12) 124 SMSC LAN9220
DATASHEET
5.5.10 Special Control/Status Indications
Index (In Decimal): 27 Size: 16-bits
ADDRESS DESCRIPTION MODE DEFAULT
15 Override AMDIX Strap
0 - AMDIX_EN (pin 52) enables or disables HP Auto MDIX
1 - Override pin 52. PHY Register 27.14 and 27.13 determine MDIX
function
RW 0
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.
RW 0
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.
RW 0
12:11 Reserved: Write as 0. Ignore on read. RW 0
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.
RW,
NASR
0
9-5 Reserved: Write as 0. Ignore on read. RW 0
4 XPOL: Polarity state of the 10Base-T:
0 - Normal polarity
1 - Reversed polarity
RO 0
3:0 Reserved: Read only - Writing to these bits have no effect. RO XXXXb