Motorola MVME2400 manual Ethernet Interface

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Functional Description

Ethernet Interface

The MVME240x module uses Digital Equipment’s DECchip 21143 PCI Fast Ethernet LAN controller to implement an Ethernet interface that supports 10Base-T/100Base-TX connections, via an RJ45 connector on the front panel. The balanced differential transceiver lines are coupled via on-board transformers.

Every MVME240x is assigned an Ethernet station address. The address is $08003E2xxxxx, where xxxxx is the unique 5-nibble number assigned to the board (i.e., every board has a different value for xxxxx).

Each MVME240x displays its Ethernet station address on a label attached to the base board in the PMC connector keepout area just behind the front panel. In addition, the six bytes including the Ethernet station address are stored in the NVRAM (BBRAM) configuration area specified by boot ROM. That is, the value 08003E2xxxxx is stored in NVRAM. The MVME240x debugger, PPCBug, has the capability to retrieve the Ethernet station address via the CNFG command.

Note The unique Ethernet address is set at the factory and should not be changed. Any attempt to change this address may create node or bus contention and thereby render the board inoperable.

If the data in NVRAM is lost, use the number on the label in the PMC connector keepout area to restore it.

For the pin assignments of the 10Base-T/100Base-TX connector, refer to Appendix C.

At the physical layer, the Ethernet interface bandwidth is 10Mbit/second for 10Base T. For the 100Base TX, it is 100Mbit/second. Refer to the BBRAM/TOD Clock memory map description in the MVME2400-Series VME Processor Module Programmer’s Reference Guide for detailed programming information.

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