8-bit MicrocontrollersのトピックRe: TPM V3 initialisation

TPM V3 initialisation

Lj_cyril — Thu, 18 Jun 2009 22:51:29 GMT

Hi evrybody,

I use the TPM module version 3 on a 9S08AC60 in PWM edge aligned methode

and i have some trouble with the setup of this module.

Here is my code :

//setup timer for PWM leds
TPM1MOD=MAX_VALUE_PWM-2;
TPM1SC=0x08;

//setup timer PWM led by led
TPM1C0V=0;
TPM1C2V=0;
TPM1C3V=0;

TPM1C0SC=0x24;
TPM1C2SC=0x24;
TPM1C3SC=0x24;

and after to change the duty cycle

        TPM1C0V=table_cpt_pwm[0];
        TPM1C2V=table_cpt_pwm[2];
        TPM1C3V=table_cpt_pwm[1];

My trouble is that when i reset my CPU, i can see 1 duty cycle

at 0. and after all works fine.

Any idea ??

Thanks for your help

Re: TPM V3 initialisation

Harman — Wed, 01 Dec 2010 21:43:37 GMT

Please how did you solve the mentioned problem. I have the same one now. Thank you very much.

Jan

Re: TPM V3 initialisation

bigmac — Wed, 01 Dec 2010 22:11:17 GMT

Hello Jan,

As the TPM module provides buffered PWM operation, the observed behavior is correct - the duty cycle will not change until the next TPM overflow occurs. If you need immediate update of a new channel register value, disable the TPM module before doing the update.

During TPM initialisation, you should consider that the TPM1SC register be the final one to be written, to enable the module.

Regards,

Mac