CCS/TMS320F28377D: F28377D: Miss sometimes a off phase in PWM

Tool/software: Code Composer Studio

Hello,

I try to realize a motor control in two motor with PWM.

In PWM signals, miss sometimes off phase.

Configuration description:

CPU at 200MHz

PWM initialization:

• PWM1 Master in GPIO163 and GPIO164  (PHSEN = 0)

• PWM2 Slave in GPIO165 and GPIO166_

• PWM3 Slave in GPIO167 and GPIO168

• PWM10 Slave in GPIO145 and GPIO146

• PWM11 Slave in GPIO147 and GPIO148

• PWM12 Slave in GPIO149 and GPIO150

PWM Period, 40µs with a Up-Down count mode. (TBPRD = 4000)

A dead-band is set to 1µs.

To have a small pressure point in a PSMS motor, the duty cycle are set around 50%:

• PWM10, CMPA = 2040

• PWM11, CMPA = 1980

• PWM12, CMPA = 1980

Software execution:

After initialization (DSP, GPIO mux, PWM):

• While (1) without interruption (Only a software loop)

Observation in oscilloscope in PWM10a, PWM11a and PWM12a.

Thank’s for your help.

Philippe HENNEQUIN

 (PHSEN = 0)