topic Re: working with pwm channels - mc9s08sh32 in Processor Expert Software

working with pwm channels - mc9s08sh32

shany — Thu, 10 Nov 2011 23:34:49 GMT

Hello,

I'm working on MCU - mc9s08sh32 and I want to operate 3 pwm channels - PTA6_TPM2CH0, PTB5_TPM1CH1, PTA7_TPM2CH1.

My problem is with the first and last channels ( PTA6 + PTA7 ) - they have a shared counter (TPM2) and I don't really know how to control their pwm ratio. When I enable both of them - each with different pwm ratios - one of them is off and sometimes there is some pwm ratio but I don't know how to predict it.

Does anybody have an idea what to do?

Does anybody have a sample project with these pwm channels?

Thanks,

shany

Re: working with pwm channels - mc9s08sh32

ProcessorExpert — Fri, 11 Nov 2011 00:34:22 GMT

Hello,

I am not aware of such issue with PWM component. However could you please share here your project including more detailed description.

best regards
Vojtech Filip
Processor Expert Support Team

Re: working with pwm channels - mc9s08sh32

shany — Sun, 13 Nov 2011 13:48:02 GMT

Hello,

Here's a more detailed description of my problem -

When I try to activate all 3 pwm channels on 100% ratio - the code is :

pwm1_SetRatio8(0);
pwm2_SetRatio8 (0);
pwm3_SetRatio8 (0);

pwm1_Enable();
pwm2_Enable();
pwm3_Enable();

however, the outcome is sometimes correct - meaning that all 3 pwm channels are on 100% ratio, and in other times the outcome is that only pwm1+2 are on 100% ratio while pwm3 is off completely (pwm2 + 3 are the ones with the shared counter, as I mentioned in the previous message).

Another problem - when I perform the following code -

pwm1_SetRatio8(255);
pwm2_SetRatio8 (25);
pwm3_SetRatio8 (200);

pwm1_Disable();

pwm2_Enable();
pwm3_Enable();

again, the outcome is sometimes correct and in other times pwm2 + pwm 3 are on 100% and not in the required pulse ratio.

I hope there are enough details here... please tell me if you need further information.

Thanks alot,

Shany

Re: working with pwm channels - mc9s08sh32

ProcessorExpert — Mon, 21 Nov 2011 23:05:00 GMT

Hello,

as I wrote before. Could you please post here your project? Please note that it will significantly reduce my time on your issue.

best regards
Vojtech Filip
Processor Expert Support Team