IO speeds

[YahooArchive]

from data sheet of LPC1756 ;
it says; max rise & fall time is: 5ns for I/O pins (when configured as
output)... It makes a lot more then 1 million operations/sec. for output...
i.e.; with 25 million Basic instructions per sec. whay can't I reach to 10 - 12
mhz of square wave output from those pins???

what I'm looking for is a way to reach perfect S-curves for motion control...4
mhz resolution for S-curve timing is good enough, and 8 is perfect ...

[YahooArchive]

For motion control you want to use the motor PWM or PWM hardware channels.

I hadn't updated the bit-banging spec for the SuperPRO, just hadn't gotten
around to running a test.

Just did it now and I can get up to 4 MHz toggle rates in BASIC, its possible to
do better in assembly language.

Rise and fall times really are independent of toggle rates, and are function of
the drivers, which these days are often slowed down to reduce EMI
radiated(that's for FCC).

> it says; max rise & fall time is: 5ns for I/O pins (when configured as
output)... It makes a lot more then 1 million operations/sec. for output...
> i.e.; with 25 million Basic instructions per sec. whay can't I reach to 10 -
12 mhz of square wave output from those pins???
>
> what I'm looking for is a way to reach perfect S-curves for motion control...4
mhz resolution for S-curve timing is good enough, and 8 is perfect ...
>