Sun Quad FastEthernet SBus Adapter Installation and User's Guide

Driver Parameter Values and Definitions

This section describes the parameters and settings for the qfe device driver. Table C-1 lists these parameters.

Table C-1 qfe Driver Parameter, Status, and Descriptions


Parameter	Status	Description
`transceiver_inuse`	Read only	Defines the current status
`link_status`	Read only	Defines the current status
`link_speed`	Read only	Defines the current status
`link_mode`	Read only	Defines the current status
`ipg1`	Read and write	Inter-packet gap parameter
`ipg2`	Read and write	Inter-packet gap parameter
`use_int_xcvr`	Read and write	Operational mode parameter
`pace_size`	Read and write	Operational mode parameter
`adv_autoneg_cap`	Read and write	Operational mode parameter
`adv_100fdx_cap`	Read and write	Operational mode parameter
`adv_100hdx_cap`	Read and write	Operational mode parameter
`adv_10fdx_cap`	Read and write	Operational mode parameter
`adv_10hdx_cap`	Read and write	Operational mode parameter
`autoneg_cap`	Read only	Local transceiver auto negotiation capability
`100fdx_cap`	Read only	Local transceiver capability of the hardware
`100hdx_cap`	Read only	Local transceiver capability of the hardware
`10fdx_cap`	Read only	Local transceiver capability of the hardware
`10hdx_cap`	Read only	Local transceiver capability of the hardware
`lp_autoneg_cap`	Read only	Link partner auto negotiation capability
`lp_100fdx_cap`	Read only	Link partner capability
`lp_100hdx_cap`	Read only	Link partner capability
`lp_10fdx_cap`	Read only	Link partner capability
`lp_10hdx_cap`	Read only	Link partner capability
`instance`	Read and write	Device instance
`lance_mode`	Read and write	Additional delay before transmitting a packet
`ipg0`	Read and write	Additional delay before transmitting a packet

Defining the Current Status

The read-only parameters described in Table C-2 explain the operational mode of the interface. These parameters define the current status.

Table C-2 Read-Only Parameters Defining the Current Status


Parameter	Values	Description
`link_status`	0 1	Current link status = Link down = Link up
`link_speed`	0 1	Valid only if the link is up = 10 Mbps = 100 Mbps
`link_mode`	0 1	Valid only if the link is up = Half duplex = Full duplex

Inter-Packet Gap Parameters

The Fast Ethernet Parallel Port SCSI (FEPS) ASIC supports the programmable Inter-Packet 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 auto-negotiation protocol, is 10 Mbps. When the link speed is 100 Mbps, the total IPG is 0.96 microseconds.

Table C-3 lists the default values and allowable values for the inter-packet gap (IPG) parameters ipg1 and ipg2.

Table C-3 Read-Write Inter-Packet Gap Parameter Values and Descriptions


Parameter	Values (Byte-time)	Description
`ipg1`	0, 255	`ipg1` = 8 (default at initialization)
`ipg2`	0, 255	`ipg2` = 4 (default at initialization)

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.)

If your network has systems that use longer IPG (the sum of ipg1 and ipg2) and if those machines seem to be slow in accessing the network, increase the values of ipg1 and ipg2 to match the longer IPGs of other machines.

Defining an Additional Delay Before Transmitting a Packet Using `lance_mode` and `ipg0`

The Fast Ethernet Parallel Port SCSI (FEPS) ASIC supports a programmable mode called lance_mode. The ipg0 parameter is associated with lance_mode.

After a packet is received with lance_mode enabled (default) an additional delay is added by setting the ipg0 parameter 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 delay set by ipg0 helps to reduce collisions. Systems that have lance_mode enabled might not have enough time on the network.

If lance_mode is disabled, the value of ipg0 is ignored and no additional delay is set. Only the delays set by ipg1 and ipg2 are used. Disable lance_mode if other systems keep sending a large number of back-to-back packets.

You can add the additional delay by setting the ipg0 parameter from 0 to 31, which is the nibble time delay. Note that nibble time is the time it takes to transfer four bits on the link. If the link speed is 10 Mbps, nibble time is equal to 400 ns. If the link speed is 100 Mbps, nibble time is equal to 40 ns.

For example, if the link speed is 10 Mbps, and you set ipg0 to 20 nibble times, multiply 20 by 400 ns to get 800 ns. If the link speed is 100 Mbps, and you set ipg0 to 30 nibble-times, multiply 30 by 40 ns to get 120 ns.

Table C-4 defines the lance_mode and ipg0 parameters.

Table C-4 Parameters Defining lance_mode and ipg0


Parameter	Values	Description
`lance_mode`	0 1	`lance_mode` disabled `lance_mode` enabled (default)
`ipg0`	0-31 [The default value is 16 nibble-times, which is 6.4 microseconds for 10 Mbps and 0.64 microseconds for 100 Mbps.]	Additional IPG before transmitting a packet (after receiving a packet)

Operational Mode Parameters

Table C-5 describes the operational mode parameters and their default values.

Table C-5 Operational Mode Parameters


Parameter	Values	Description
`adv_autoneg_cap`	0 1	Local transceiver capability advertised by the hardware = Forced mode = Auto-negotiation (default)
`adv_100fdx_cap`1	0 1	Local transceiver capability advertised by the hardware; read/write parameter = Not 100Mbit/sec full-duplex capable (default in the Solaris 2.5 and 2.5.1 software environments) = 100Mbit/sec full-duplex capable (default in the Solaris 2.6 software environment)
`adv_100hdx_cap`1	0 1	Local transceiver capability advertised by the hardware; read/write parameter = Not 100Mbit/sec half-duplex capable = 100Mbit/sec half-duplex capable (default)
`adv_10fdx_cap`1	0 1	Local transceiver capability advertised by the hardware; read/write parameter = Not 10Mbit/sec full-duplex capable (default) = 10Mbit/sec full-duplex capable
`adv_10hdx_cap` [The priority (in descending order) for these parameters is: `adv_100fdx_cap`, `adv_100hdx_cap`, `adv_10fdx_cap`, and `adv_10hdx_cap.`]	0 1	Local transceiver capability advertised by the hardware; read/write parameter = Not 10Mbit/sec half-duplex capable = 10Mbit/sec half-duplex capable (default)

Defining the Number of Back-to-Back Packets to Transmit

The pace_size parameter (see Table C-6) defines the maximum number of back-to-back packets you can transmit at one time. If the value is zero, there is no limit to the number of back-to-back packets that can be transmitted.

Table C-6 Back-to-back Packet Transmission Capability


Parameter	Values	Description
`pace_size`	1 to 255 0	= Number of back-to-back packets transmitted at one time = No limit to the number of back-to-back packets that can be transmitted (default)

Reporting Transceiver Capabilities

Table C-7 describes the read-only transceiver capabilities. These parameters define the capabilities of the hardware. The internal transceiver can support all of these capabilities.

Table C-7 Read-Only Transceiver Capabilities


Parameter	Values	Description
`autoneg_cap`	0 1	Local transceiver capability of the hardware = Not capable of auto-negotiation = Auto negotiation capable
`100fdx_cap`	0 1	Local transceiver capability of the hardware; initialized at startup = Not 100Mbit/sec full-duplex capable = 100Mbit/sec full-duplex capable
`100hdx_cap`	0 1	Local transceiver capability of the hardware; initialized at startup = Not 100Mbit/sec half-duplex capable = 100Mbit/sec half-duplex capable
`10fdx_cap`	0 1	Local transceiver capability of the hardware; initialized at startup = Not 10Mbit/sec full-duplex capable = 10Mbit/sec full-duplex capable
`10hdx_cap`	0 1	Local transceiver capability of the hardware; initialized at startup = Not 10Mbit/sec half-duplex capable = 10Mbit/sec half-duplex capable

Reporting the Link Partner Capabilities

Table C-8 describes the read-only link partner capabilities.

Table C-8 Read-Only Link Partner Capabilities


Parameter	Values	Description
`lp_autoneg_cap`	0 1	= No auto-negotiation = Auto-negotiation
`lp_100fdx_cap`	0 1	= No100Mbit/sec full-duplex transmission = 100Mbit/sec full-duplex
`lp_100hdx_cap`	0 1	= No 100Mbit/sec half-duplex transmission = 100Mbit/sec half-duplex
`lp_10fdx_cap`	0 1	= No 10Mbit/sec full-duplex transmission = 10Mbit/sec full-duplex
`lp_10hdx_cap`	0 1	= No 10Mbit/sec half-duplex transmission = 10Mbit/sec half-duplex

If the link partner is not capable of auto-negotiation (when lp_autoneg_cap is 0) the information described in Table C-8 is not relevant and the parameter value = 0.

If the link partner is capable of auto-negotiation (when lp_autoneg_cap is 1) then the speed and mode information is displayed when you use auto-negotiation and get the link partner capabilities.