Hi Gordon,

Going by your queries, I think it will also be quite useful for you to study the AC characterisitics and the pulse waveforms of any 8052 - particularly the sequence during external memory read and write. This will clearly show you how the processor swings its #RD and #WR signals with reference to the ALE and DATA signals.

Suggest refer to some plain vanilla type like the 80c31 or 80c51 to keep matters simple.


Raghu