LAN Controller Registers (B1:D8:F0)
7-20
Intel
82801BA ICH2 Datasheet
7.2.12
General Status Register
Offset Address:
Default Value:
1Dh
N/A
Attribute:
Size:
RO
8 bits
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.
Bit
Description
7:3
Reserved.
2
Duplex Mode.
This bit indicates the wire duplex mode.
1 = Full duplex
0 = Half duplex
1
Speed.
This bit indicates the wire speed:
1 = 100 Mbps
0 = 10 Mbps
0
Link Status Indication.
This bit indicates the status of the link:
1 = Valid
0 = Invalid
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.
12
Transmit Underrun Errors
A transmit underrun occurs because the system bus cannot keep up
with the 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.
16
Transmit Lost 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.
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