Hello.

Here's simple code:

Code:
define OSC 4
TRISB = %00000000
charte var PORTB.2
gamorte var PORTB.3

AGAIN:
pulsout charte,1
pauseus 100
pulsout gamorte,1
pause 1000
pulsout charte,1
pauseus 200
pulsout gamorte,1
pause 1000
pulsout charte,1
pauseus 300
pulsout gamorte,1
pause 1000


GOTO AGAIN
When run on 16F628A, instead of 100, 200 and 300 uS delays, it gives: 290, 400, 490us delay, measured with digital scope.

I've modified code for 16F819, for 8mhz oscillator, by changing to: define OSC 8 and adding: OSCCON=%01110100

In this case, linearity improved, but PAUSEUS are still out of definitions:

100uS gives 270 uS
200uS gives 370 uS
300uS gives 470 uS

Why this happens and what I'm doing wrong?