MPC5xxxのトピックRe: PWM on MPC5674F not working

PWM on MPC5674F not working

vincentbergeron — Thu, 07 May 2015 14:14:27 GMT

I am trying to output PWM en EMIOS CH4 and nothing is happening. Here is my code:

initEMIOS(){

EMIOS.MCR.B.GPRE = 63; // Divide by 64

EMIOS.MCR.B.GTBE = 1; // Enable global time base

EMIOS.MCR.B.FRZ = 1; // Enable freeze mode when debugging

EMIOS.MCR.B.GPREN = 1; // Enable EMIOS Prescaler

}

initEMIOSCh23(){

EMIOS.CH[23].CADR.R = 99; // 100 clocks

EMIOS.CH[23].CCR.B.MODE = 0x50; // Modulus buffer counter

EMIOS.CH[23].CCR.B.BSL = 0x3; // All channels internal counter

EMIOS.CH[23].CCR.B.UCPRE = 0; // Divide by 1

EMIOS.CH[23].CCR.B.UCPREN = 1; // Enable prescaler

}

initEMIOSCh4(){

EMIOS.CH[4].CADR.R = 500;

EMIOS.CH[4].CBDR.R = 1000;

EMIOS.CH[4].CCR.B.BSL = 0; // Use counter channel A

EMIOS.CH[4].CCR.B.EDPOL = 1;

EMIOS.CH[4].CCR.B.MODE = 0x20; // OPWM

SIU.PCR[183].R = 0x0600; // Ouput and primary function

}

int main(){

initEMIOS();

initEMIOSCh23();

initEMIOSCh4();

while(1){}

}

Re: PWM on MPC5674F not working

alexvinchev — Fri, 08 May 2015 13:22:47 GMT

Did you feed clock to the EMIOS?

Check http://cache.freescale.com/files/microcontrollers/doc/app_note/AN4830.pdf , there is EMIOS example, as far as I remember, it was working on my side, when I've tested...

Re: PWM on MPC5674F not working

vincentbergeron — Fri, 08 May 2015 14:14:12 GMT

I am trying to find the software example listed in the AN4830 document on the freescale site, but I cannot find it.. Can you send me the link please

Re: PWM on MPC5674F not working

vincentbergeron — Fri, 08 May 2015 18:06:37 GMT

How do you feed the clock to the EMIOS??

Re: PWM on MPC5674F not working

PetrS — Mon, 11 May 2015 07:49:30 GMT

Hi,

the channel 23 is used as time base for your channel 4 in OPWM mode, so channel 4’s CADR/CBDR registers have to be set to value between 1 and EMIOS.CH[23].CADR.R to be able to perform a match.

With your setting matching never happen, thus have no toggle on output.

Regards,

Petr