Strange Behavior 12F1822

[sayzer]

"When i'm using 16MHz internal frequency (OSCCON = 01111000) everthing works fine."

You thought everything worked fine.

I see no DEFINE OSC 16 or 32.

"My programm does software-pwm, lighting 5 LED's up and down."

May I suggest that you use DT's MIBAM for these 5-LEDS ?
With 32Mhz, you can get high refresh rate with MIBAM.

[Dave]

nobner, that is in this line of code?
OSCCON = 110000

Apparently when copying text It did not allow the correct sequence to be copied. Look at the embeded code sequence at the line where you are setting OSCCON.

[sayzer]

nobner, that is in this line of code?
OSCCON = 110000

Apparently when copying text It did not allow the correct sequence to be copied. Look at the embeded code sequence at the line where you are setting OSCCON.

It is something with the system here. Sometimes percent sign, %, disappears in code block.

Norbert has it correct in code block.

I guess it will be fixed soon.

[HenrikOlsson]

Hi,

This sounds like the classic RMW issue.
Instead of aliasing your LEDn variables to the PORTA register, try alias them to the LATA register and see what happens.
Do a search for read modify write if you don't know what RMW means.

/Henrik.

[nobner]

Hello,
did a wrong measurement yesterday.
Only Ports RA0 and RA2 have the spikes.
All other ports are working correct at 16MHz and 32MHz.
I added DEFINE OSC 32 - nothing changed.
I replaced the aliases for the LED with direct ports in the programm (PORTA.0=1) - nothing changed.
Now i'll search for RMW as recommended.

[HenrikOlsson]

Hi,
Replacing the alias with direct port adress doesn't make any difference. What I suggested was to write to the LAT register instead of the PORT register, ie:
LATA.0=1 instead of PORTA.0=1
or created the alias pointing on the LAT register instead of the PORT regsiter:
LED1 VAR LATA.0 instead of LED1 VAR PORTA.0

[nobner]

Hi Henrik,
thank you for your great help, writing the LAT register did the job. Signals are perfect now.
I also found now a second solution for the problem - using the "high porta.0" and "low porta.0" works also.
Thank you very much,
best regards
Norbert