TMS470MF03107: PWM signals' period(& duty) generation based on HET displayed on Oscilloscope screen is very different from period(& duty) set in CCS project files generated from HALCogen.

Hi Team,

tms470mf03107 HET module pin description:

PCB 4 PWM pin layout:

After ZOOM in：

HET Global Timing Configuration is as follows：

The main function is as follows:

int main(void)

{

/* USER CODE BEGIN (2) */

    hetInit();

            pwmSetSignal(pwm0,set_pwm0);

            pwmSetSignal(pwm1,set_pwm1);

            pwmSetSignal(pwm2,set_pwm2);

            pwmSetSignal(pwm3,set_pwm3);

           // pwmSetSignal(pwm4,set_pwm4);

           // pwmSetSignal(pwm5,set_pwm5);

           // pwmSetSignal(pwm6,set_pwm6);

           // pwmSetSignal(pwm7,set_pwm7);

            pwmStart(pwm0);

            pwmStart(pwm1);

            pwmStart(pwm2);

            pwmStart(pwm3);

           // pwmStart(pwm4);

           // pwmStart(pwm5);

           // pwmStart(pwm6);

          //  pwmStart(pwm7);

            pulse_pwm0 = pwmGetSignal(pwm0);

            pulse_pwm1 = pwmGetSignal(pwm1);

            pulse_pwm2 = pwmGetSignal(pwm2);

            pulse_pwm3 = pwmGetSignal(pwm3);

          //  pulse_pwm4 = pwmGetSignal(pwm4);

          //  pulse_pwm5 = pwmGetSignal(pwm5);

           // pulse_pwm6 = pwmGetSignal(pwm6);

           // pulse_pwm7 = pwmGetSignal(pwm7);

//        }

/* USER CODE END */ 

}

4 PWM signal Period set is the same with the PWM signals generated by program,covering the minimum(482us) and maximum period(1736044us) i want.

BUT the real PWM signal waves are as follows:

S1(PWM0,het[11]):

Constantly HIGH level：

S2(PWM1,het[12]):

displayed PWM wave output period is 290us，which is HALF of the set period 578us：

S3(PWM2,het[13])：

displayed PWM wave output period is 720ms，which is HALF of the set period 1446703us：

S4(PWM3,het[14])：

displayed PWM wave output period is 880ms，which is HALF of the set period 1736044us

When the global timing configuration is as follows,which is default setting(other configuration stays the same):

PWM0 and PWM1 period set is the same with the program-generated value,but program-generated value of PWM2 and PWM3 duty&period are abnormal compared with the duty&period set.You can see as follows:

Oscilloscope Screen displays are as follows:

S1:period=960us,TWICE of the set period 480us

S2:period=1160us,TWICE if the set period 578us

S3:almost constant level 376ms TWICE of 188414us

S4:duty abnormal, constant HIGH level:

Here in order for simplification, some other test and description is as follows：

HET Global Timing Configuration ONE:

4 PWM signal Period set is 10000us(10ms),which is the same with the PWM signals generated：  

But the real PWM pulse waves are as follows:

S1(PWM0,het[11])：NO PWM wave shape displayed on Oscilloscope screen,but pulled HIGH constantly.

S2(PWM1,het[12])，S3(PWM2,het[13])，S4(PWM3,het[14]):PWM waves are displayed as follows on screen,but pulse period(5000us or 5ms) is HALF of the set period(10000us or 10ms)：

WHEN the global timing configuration TWO is as follows:

4 PWM signal Period set is 10000us(10ms),which is the same with the PWM signals generated：

But the real 4 PWM pulse waves are as follows，all having high and low level apparently,but pulse period(20000us or 20ms) is TWICE of the set period(10000us or 10ms).

All in all, I wonder, based on the certain HET timing configuration， why the generated  PWM periods are not the same with the PWM period(& duty) set by me?

Could you help check this case? Thanks.

Best Regards,

Cherry