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Parameters that define the current status, Interpacket gap parameters – Sun Microsystems FASTETHERNET 6U User Manual

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Sun Quad FastEthernet 6U CompactPCI Adapter Installation and User’s Guide • June 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)