Hi,

> OK, basically, the program ...

> What program?  Maybe you remember the context of successive messages about
> your project, but the rest of us have lots of other stuff going on, and
> you're project isn't high up on the priority list.  If you expect help from
> others, you need to make it easy for them.  No, I'm not going to dig thru
> the archives just to answer a PIClist question.  Quote the relevant parts
> of
> what you are replying to and snip the rest.  This has been said many times
> here, and should be self-evident from common sense anyway.
>

Sorry, I'm used to gmail keeping things in threads for me.  I also thought
that I had quoted the relevant parts.  I'll rephrase my question...

I am writing a program which receives serial data and manipulates portb
depending on what is received. The pic uses RA6=low to signal that it is
ready to receive the next data byte.

The interrupt handler raises RA6 when a byte is received, the main loop
checks the UARTs 'transmission received' flag (PIR,5).  This flag never
seems to get set.  If I raise a flag in the interrupt handler, then it works
ok, but why doesn't checking PIR,5 work?

If i include the code, would that be helpful?
a little more detailed description is below...

Thanks
Nick


Initially, RA6 is low.

The main loop waits for a byte to be received*.  Once this happens, it can
read the byte out of RCREG and then set RA6=low.  This lets the sender know
that it can send another byte if it wants.  the pic then goes off and
manipulates portb, which involves delays and things.

When a byte is received, the interrupt handler sets RA6=high, to signal to
the sender not to send anything else until the main loop is ready for it.

* if the main loop detects a byte having arrived by checking a flag set in
the interrupt handler, it works.  if the main loop detects a byte having
arrived by looking at PIR,5 it doesn't work.
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