"Jim Thompson" wrote in message
...

An XOR is a convenient structure to allow a control signal to invert
or non-invert another signal.

Trouble is (as classically done) inverting has 3 stage delays, while
non-inverting has only 2.

Anyone know of a configuration that has symmetric delays?

Thanks!

(I'm rolling my own at the device level so anything goes :-)

...Jim Thompson
---------------------------

One other comment here.

This whole thing may be BS as NAND gates were a more natural logic using
transistors as they took less transistors to create. NAND and NOR gates can
be accomplished with one stage or transistors.

AND and simple OR gates had an extra inversion stage to make them operate
with their logic and thus had more propagation delay.

Been a long time since I studied the inside circuitry of logic gate
families. My boss insisted we knew everything about an IC before tackling
any repairs. Of course we usually fixed the problem when he went to answer
the phone. Got years of chasing electrons experience, though.


mike