Description

The EtherLink III driver provides low-level communication between EROS and the EtherLink adapter. It provides several functions, most important ones being read and write. The driver accepts transmit data in Ethernet or IEEE 802.3 format. The invoker will supply a complete frame, with exception of the CRC field. The driver returns receive data without interpreting it.

Operations

Read (OC = 1)

Receives data from network adapter. Returns the alleged type of the key.

Data will not be interpreted by the driver and will simply be returned to invoker.

Reply	B*	Data bytes of one received Ethernet packet.
Result	OK	Operation completed successfully.

Write Ethernet Frame (OC = 2)

Transmits data in Ethernet format with network adapter.

Data must be in valid Ethernet frame format, i.e. no less than 60 bytes and no longer than 1514 bytes. Driver provides CRC field. If the source address field does not match adapter's node address, an error result will be returned, but the packet will be transmitted regardless.

Request	B*	Data to be transmitted.
Result	OK	Operation completed successfully.
	TX_INCORRECT_SRC_ADDR	Operation completed successfully. Error result returned to inform invoker that source address field in packet does not match adapter's node address.
	TX_INCORRECT_PKT_LEN	Operation incomplete. The packet length is invalid for Ethernet/IEEE 802.3 encapsulation.

Write IEEE 802.3 Frame (OC = 4)

Transmits data in IEEE 802.3 format with network adapter.

Data must be in valid IEEE 802.3 frame format, i.e. no less than 60 bytes and no longer than 1514 bytes. Driver provides CRC field. If the source address field does not match adapter's node address, an error result will be returned, but the packet will be transmitted regardless.

Request	B*	Data to be transmitted.
Result	OK	Operation completed successfully.
	TX_INCORRECT_SRC_ADDR	Operation completed successfully. Error result returned to inform invoker that source address field in packet does not match adapter's node address.
	TX_INCORRECT_PKT_LEN	Operation incomplete. The packet length is invalid for Ethernet/IEEE 802.3 encapsulation.

Reset (OC = 16)

Places network adapter in known state. Does not reconfigure options set by 3Com configuration utility.

Result

OK

Operation completed successfully.

Statistics (OC = 17)

Gathers statistical information about adapter.

Reply	H	Total bytes transmitted successfully.
	H	Total bytes received successfully. This statistic excludes runts, overruns, and frames discarded before completion.
	B	Total transmit deferrals.
	B	Total frames received successfully. This statistic excludes runts, overruns, and frames discarded before completion.
	B	Total frames transmitted successfully with no errors.
	B	Total receive frames discarded due to RX FIFO overrun. This statistic includes only those packets seen by host as RX overruns. It does not include those discarded without a trace because the RX FIFO is completely full.
	B	Total late collisions on transmit.
	B	Total frames transmitted after one collision.
	B	Total frames transmitted after multiple collisions.
	B	Total frames transmitted with no CD heartbeat.
	B	Total carrier sense lost during transmission.
Result	OK	Operation completed successfully.

Get Ethernet Address (OC = 18)

Returns the 3Com node address of the adapter.

Reply	H	First two bytes of the node address.
	H	Second two bytes.
	H	Last two bytes.
Result	OK	Operation completed successfully.

Partition RAM (OC = 19)

Specifies how the external SRAM of a revision B adapter should be split up into TX FIFO/RX FIFO storage. The partition is defined as the ratio of transmit RAM to receive RAM (TX/RX).

Care should be taken in using this operation. The RAM partition parameter can only be changed with both FIFOs in reset state. That means no input or output since the transmitter and receiver were reset. This operation will reset both the transmitter and receiver, then update the parameter as desired by the invoker. The resets will empty the respective FIFOs, disable the Ethernet controller, and abort reception if a packet is currently being received or transmission if a packet is being transmitted.

Request	ThreeToFive	3:5 (default on power-up/reset) Legal only if RAM Size is 8 KB.
	OneToThree	1:3 Legal only if RAM Size is 8 KB.
	OneToOne	1:1
Result	OK	Operation completed successfully.
	INCORRECT_RAM_SIZE	Operation incomplete. RAM size is invalid for desired partition. The receiver and transmitter are intact and are not reset.