--- drew@technteach.com wrote:

> The 82C54 is cheap.
> 
> What I want to do is some of the CCP stuff but with a 32 bit counter,
> and FOsc/4 clock.  Being able to do all of it would be even better.
> 
> Tight loops, counting instructions executed, really sucks.  It would
> be
> much nicer if an interrupt routine could check a hardware counter and
> tell how long it's been since the last time we looked.
> 
> I can cascade two of the 16-bit counters in the 82C54, and it would
> be
> perfect if I could latch the values of both counters at the same
> time.
> The code to detect and compensate for the high order counter changing
> while the code is running is tricky enough that it's likely to be
> buggy.
> 
> Does any have any better idea for a hardware counter, or some well
> debugged code for a 32 bit counter using the 82C54?
> 
If your circuit has some discrete logic already in it, use a CPLD to
eliminate that logic and act as a 32 bit counter.  That is what I would
suggest.  The nice thing about such an option is you can make it behave
exactly how you need it to behave.  I suggest hitting a few people such
as altera and Xilinx websites and find what free stuff you can use to
make something close to what you want. :)



Stephen R. Phillips was here
Please be advised what was said may be absolutely wrong, and hereby this disclaimer follows.  I reserve the right to be wrong and admit it in front of the entire world.


	
		
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