82801FB Datasheet, PDF (307/786 Pages) Intel Corporation – Intel I/O Controller Hub 6 (ICH6) Family

LAN Controller Registers (B1:D8:F0)
Table 8-6. Statistical Counters (Sheet 2 of 2)
ID
Counter
Description
48
Receive Resource
Errors
This counter contains the number of good frames discarded due to
unavailability of resources. Frames intended for a host whose Receive
Unit is in the No Resources state fall into this category. If the LAN
controller is configured to Save Bad Frames and the status of the received
frame indicates that it is a bad frame, the Receive Resource Errors
counter is not updated.
52
Receive Overrun
Errors
This counter contains the number of frames known to be lost because the
local system bus was not available. If the traffic problem persists for more
than one frame, the frames that follow the first are also lost; however,
because there is no lost frame indicator, they are not counted.
56
Receive Collision
Detect (CDT)
This counter contains the number of frames that encountered collisions
during frame reception.
This counter contains the number of received frames that are shorter than
60
Receive Short Frame
Errors
the minimum frame length. The Receive Short Frame Errors counter is
mutually exclusive to the Receive Alignment Errors and Receive CRC
Errors counters. A short frame will always increment only the Receive
Short Frame Errors counter.
64
Flow Control Transmit
Pause
This counter contains the number of Flow Control frames transmitted by
the LAN controller. This count includes both the Xoff frames transmitted
and Xon (PAUSE(0)) frames transmitted.
68
Flow Control Receive
Pause
This counter contains the number of Flow Control frames received by the
LAN controller. This count includes both the Xoff frames received and Xon
(PAUSE(0)) frames received.
This counter contains the number of MAC Control frames received by the
72
Flow Control Receive LAN controller that are not Flow Control Pause frames. These frames are
Unsupported
valid MAC control frames that have the predefined MAC control Type
value and a valid address but has an unsupported opcode.
76
Receive TCO Frames
This counter contains the number of TCO packets received by the LAN
controller.
78 Transmit TCO Frames This counter contains the number of TCO packets transmitted.
The Statistical Counters are initially set to 0 by the ICH6’s integrated LAN controller after reset.
They cannot be preset to anything other than 0. The LAN controller increments the counters by
internally reading them, incrementing them and writing them back. This process is invisible to the
processor and PCI bus. In addition, the counters adhere to the following rules:
• The counters are wrap-around counters. After reaching FFFFFFFFh the counters wrap around
to 0.
• The LAN controller updates the required counters for each frame. It is possible for more than
one counter to be updated as multiple errors can occur in a single frame.
• The counters are 32 bits wide and their behavior is fully compatible with the IEEE 802.1
standard. The LAN controller supports all mandatory and recommend statistics functions
through the status of the receive header and directly through these Statistical Counters.
The processor can access the counters by issuing a Dump Statistical Counters SCB command. This
provides a “snapshot”, in main memory, of the internal LAN controller statistical counters. The
LAN controller supports 21 counters. The dump could consist of the either 16, 19, or all 21
counters, depending on the status of the Extended Statistics Counters and TCO Statistics
configuration bits in the Configuration command.
Intel^® I/O Controller Hub 6 (ICH6) Family Datasheet
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