Changes

Since the modules described here represent the core of the FPGA, their combined simulation calls for inclusion of all other fringe modules.  Essentially the whole FPGA will have to be tested to ensure this scheme for the core is acting properly. The challenge is in the complexity of the stimulus for such simulation: whole packets will need to be sent in and possibly inter-packet Ethernet Controller Chip states tested.

Since the modules described here represent the core of the FPGA, their combined simulation calls for inclusion of all other fringe modules.  Essentially the whole FPGA will have to be tested to ensure this scheme for the core is acting properly. The challenge is in the complexity of the stimulus for such simulation: whole packets will need to be sent in and possibly inter-packet Ethernet Controller Chip states tested.

Proper reading of packets can be implemented with a module inside the Transceiver that releases its test buffer byte by byte to simulate the AutoRead mode. A more extensive simulation would be useful which includes the testing of the Intel Muxed bus and which would test packet assembly, sending and Ethernet polling procedures.

A stripped down emulator for the Ethernet Controller has been written. It is a essentially a set of registers with a Multiplexed Intel bus communication layer and packet file read/write layers. These registers, however, are not passive memory banks but include "events" that are triggered by particular register states. For instance writing to registers designated to make up a receive buffer pointer actually delivers the requested byte from the buffer to the appropriate control register to be available for a subsequent request. A simple interrupt system (stimulated externally by the simulation layer) has also been included.