Sun Microsystems 806-2997-10, Installation And User Manual

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34 Sun Quad FastEthernet 3U CompactPCI Adapter Installation and User Guide • December 2000
Parameters that Define the Current Status
The read-only parameters described in
TABLE B-2
explain the operational mode of the
interface. The following parameters display the current status of an interface.
Interpacket Gap Parameters
The adapter’s PCI fast ethernet and expansion (PFEX) ASIC supports programmable
Interpacket Gap (IPG) parameters
ipg1
and
ipg2
. The total IPG is the sum of
ipg1
and
ipg2
. The total IPG is 9.6 microseconds when the link speed set by the
autonegotiation protocol is 10 Mbps. When the link speed is 100 Mbps, the total IPG
is 0.96 microseconds.
TABLE B-3
lists the default values and allowable values for the IPG parameters
ipg1
and
ipg2
.
By default, the driver sets
ipg1
to 8-byte time and
ipg2
to 4-byte time, which are
the standard values. (Byte time is the time it takes to transmit one byte on the link,
with a link speed of either 100 Mbps or 10 Mbps.)
TABLE B-2
Read-Only Parameters Defining the Current Status
Parameter Description
link_status
Current link status.
0 = Link down
1 = Link up
link_speed
Current link speed (valid only if the link is up).
0 = 10 Mbps
1 = 100 Mbps
link_mode
Current link mode (valid only if the link is up).
0 = Half duplex
1 = Full duplex
TABLE B-3
Read-Write Interpacket Gap Parameter Values and Descriptions
Parameter
Values
(Byte-time)
Description
ipg1
0 to 255
ipg1
= 8 (default at initialization)
ipg2
0 to 255
ipg2
= 4 (default at initialization)