82801BA Datasheet, PDF (246/498 Pages) Intel Corporation – Intel 82801BA I/O Controller Hub 2 (ICH2) and Intel 82801BAM I/O Controller Hub 2 Mobile

LAN Controller Registers (B1:D8:F0)
7.2.12
General Status Register
Offset Address: 1Dh
Default Value: N/A
Attribute:
Size:
RO
8 bits
Bit
Description
7:3 Reserved.
Duplex Mode. This bit indicates the wire duplex mode.
2
1 = Full duplex
0 = Half duplex
Speed. This bit indicates the wire speed:
1
1 = 100 Mbps
0 = 10 Mbps
Link Status Indication. This bit indicates the status of the link:
0
1 = Valid
0 = Invalid
7.2.13 Statistical Counters
The ICH2’s integrated LAN Controller provides information for network management statistics by
providing on-chip statistical counters that count a variety of events associated with both transmit
and receive. The counters are updated by the LAN Controller when it completes the processing of a
frame (i.e., when it has completed transmitting a frame on the link or when it has completed
receiving a frame). The Statistical Counters are reported to the software on demand by issuing the
Dump Statistical Counters command or Dump and Reset Statistical Counters command in the SCB
Command Unit Command (CUC) field.
Table 7-6. Statistical Counters
ID
Counter
Description
0
Transmit Good
Frames
This counter contains the number of frames that were transmitted properly on
the link. It is updated only after the actual transmission on the link is
completed, not when the frame was read from memory as is done for the
Transmit Command Block status.
4
Transmit Maximum
Collisions
(MAXCOL) Errors
This counter contains the number of frames that were not transmitted
because they encountered the configured maximum number of collisions.
8
Transmit Late
Collisions
(LATECOL) Errors
This counter contains the number of frames that were not transmitted since
they encountered a collision later than the configured slot time.
A transmit underrun occurs because the system bus cannot keep up with the
12
Transmit Underrun
Errors
transmission. This counter contains the number of frames that were either
not transmitted or retransmitted due to a transmit DMA underrun. If the LAN
Controller is configured to retransmit on underrun, this counter may be
updated multiple times for a single frame.
Transmit Lost
16 Carrier Sense
(CRS)
This counter contains the number of frames that were transmitted by the LAN
Controller despite the fact that it detected the deassertion of CRS during the
transmission.
20
Transmit Deferred
This counter contains the number of frames that were deferred before
transmission due to activity on the link.
24
Transmit Single
Collisions
This counter contains the number of transmitted frames that encountered
one collision.
7-20
82801BA ICH2 and 82801BAM ICH2-M Datasheet