On Thu, 18 Jun 1998 08:51:55 -0400, you wrote:

>> Is there presently anyway I can get a Pic16c54 or any other Pic for that
>> matter to be able to execute code at 1 nanosecond per instruction?
>> If not possible with Pics are there any other microcontrollers that can
>> execute instructions this fast? Thanx in advance for for responding.
>
>This would correspond to a clock speed of 4GHz (billion cycles per second),
>since all PICs require 4 clock cycles for each instruction cycle.  To the
>best of my knowledge, there is no microprocessor on earth that would clock
>that fast.
>
>The fastest PICs are rated at a maximum external clock frequency of 33MHz,
>or 121ns instruction cycle time.
The Scenix SX parts are guaranteed at 50MHz and have been run at up to
about 120MHz, and they do 1 instruction per clock, giving 8.3nS per
instruction.  Maybe put one in a freezer & crank up the supply
voltage! 
If you really need this sort of speed you should be looking at FPGAs
instead of, or as well as, microcontrollers.
>
>All PICs can operate on an internal RC oscillator which has a fixed nominal
>value of 4MHz, or 1 usec instruction cycle time.
I wish this were true, but  only the 12cxx parts (and I think the new
14 pin devices) have internal RC, others need external R & C and are a
lot less accurate due to stray capacitance and lack of factory
calibration. 



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