Sun Microsystems 806-2989-10 manual Gigabit Forced Mode Parameter, Interpacket Gap Parameters

Gigabit Forced Mode Parameter

In 10/100 mode it was possible to disable auto-negotiation and force the link to the speed you required. With Gigabit copper interfaces this feature is also available but may require you to decide whether your side of the connection is a master or a slave. The link_master parameter will facilitate that. Usually switches will be enabled as master therefore this parameter can remain unchanged, since slave operation is the default. If this is not the case Then link_master can be used to enable ce as a master.

TABLE 4-4Forced Mode Parameter

Parameter	Description
link_master	When set to 1 this enables master operation, assuming the link
	partner is a slave.
	When set to 0 this enables slave operation, assuming the link
	partner is a slave. (default)

Interpacket Gap Parameters

The ce device supports a programmable mode called enable_ipg0.

When a driver receives a packet with enable_ipg0 set (the default), it adds an additional time delay before transmitting the packet. This delay, set by the ipg0 parameter, is in addition to the delay set by the ipg1 and ipg2 parameters. The additional ipg0 delay helps to reduce collisions.

If enable_ipg0 is disabled, the value of ipg0 is ignored and no additional delay is set. Only the delays set by ipg1 and ipg2 will be used. Disable enable_ipg0 if other systems keep sending a large number of back-to-back packets. Systems that have enable_ipg0 set might not have enough time on the network.

You can add the additional delay by setting the ipg0 parameter from 0 to 255, which is the media byte time delay.

Chapter 4 Configuring Driver Parameters 29