27 Apr
2008
27 Apr
'08
8:45 a.m.
On Sun, 2008-04-27 at 08:23 -0700, dwight elvey wrote:
Hi
I've got a funny problem with a 8251.
I've been writing 8080 code and seem to have a strange
problem.
I initialize the chip in async mode. I have a light box on the
serial wire. It is initialized to both send and recieve.
I send one character to the 8251 and it passes it to the software
on the 8080 side. I display it on the 8080 side.
I then send another character to the 8251. Nothing happens.
It won't receive until I reset it.
None of the status lights change. I can see the data light flicker.
It could be a bad part but it just doesn't seem that it would
work once and then fail to work for the second character.
It just doesn't make sense.
Is there something I'm missing about the 8251.
Dwight
That could be caused by a lot of things. Could you post the relevant
code?