Mike said:
I'm not sure your bcf TX_WPTR,4 suggestion will work... (1) My TX_WPTR variable contains values in the range of B0..BF (10110000..10111111)... (2) Even if I was using 00..0F for my RX_RPTR and RX_WPTR values, the 'unload buffer' code in the ISR might catch that momentary TX_WPTR value of 00010000 just before the bcf TX_WPTR,4 instruction in main...
1. Missed that. Should have realised that.
2. Surely, your interrupt code only changes TX_RPTR and so this won't cause a problem.
Anyway, just wanted to point out the possible problem as they are the sort of problem that suddenly crops up way down the line as timing changes.
Mike.