Software Developer’s Manual 267

Register Descriptions

PHY Port Control Register (82541xx and 82547GI/EI Only)

PPCONT (18d; R/W)

Page Received
Interrupt Enable 12 1b = Interrupt enable.
0b = Interrupt disable. R/W 0b Retain
Duplex Changed
Interrupt Enable 13 1b = Interrupt enable.
0b = Interrupt disable. R/W 0b Retain
Speed Changed
Interrupt Enable 14 1b = Interrupt enable.
0b = Interrupt disable. R/W 0b Retain
Auto-Negotiation
Error
Interrupt Enable
15 1b = Interrupt enable.
0b = Interrupt disable. R/W 0b Retain

Table 13-36. PHY Port Control Register Bit Description

Field Bit(s) Description Mode HW Rst SW Rst
Reserved 3:0 Always read as 0b. Write to 0b for
normal operation. R/W 0b 0b
TP Loopback 4Allow gigabit loopback on twisted pairs. R/W 0b 0b
Fast Downshift
Enable 5
82541EI/82547GI (B0 stepping):
Reserved, write to 0b.
82541/GI/ER and 82547GI (B1
stepping): Fast 1000 Mb to 100 Mb
downshift enable.
0b = Downshift after 16 seconds.
1b = Downshift after 10 seconds.
R/W 0b 0b
Reserved 8:6 Always read as 0b. Write to 0b for
normal operation. R/W 0b 0b
Non-Compliant
Scrambler
Compensation
9
1b = Detect and correct for non-
compliant scrambler.
0b = Detect and report non-compliant
scrambler.
R/W 0b 0b1
TEN_CRS_Select 10
1b = Extend CRS to cover GMII latency
and RX_DV.
0b = Do not extend CRS (RX_DV can
continue past CRS).
R/W 1b 1b
Reserved 11 Always write as 1b for normal operation. R/W 1b 1b
Auto-MDI-X 12
Auto-MDI-X algorithm enable.
1b = Enable Auto-MDI-X mode.
0b = Disable Auto-MDI-X mode (manual
mode).
Note: When forcing speed to 10Base-T
or 100Base-T, use manual mode. Clear
the bit and set PHY register 18, bit 13
according to the required MDI-X mode.
R/W 1b 1b

Table 13-35. PHY Interrupt Enable Bit Description

Field Bit(s) Description Mode HW Rst SW Rst