> I guess it comes down to a bit of common sense. Xtal speed VS pin
> capactiance, and because writes followed by reads take less than a clock
> cycle for the data recognition, probably closer to a Q cycle, I guess
> the NOP helps a bit - but as you mention not in every case :-)

There are *0* Q cycles between a write and a read in the next instruction.
Read data gets latched internally at the beginning of a cycle, and write
data gets written to the output latches at the end of a cycle.  If you write
something and want to read the reaction of the external circuit, you need at
least one NOP, even if the PIC output is just wired right back to the PIC
input.


********************************************************************
Olin Lathrop, embedded systems consultant in Littleton Massachusetts
(978) 742-9014, olin@embedinc.com, http://www.embedinc.com

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