Problem with Arduino DUE PWM synchronous mode

Hardware Arduino Due
3

Mark thanks for your reply

Ni it has nothing with the oscilloscope it ha ssomthing to do with

for (i = 0; i < (120);i++) { 
 g_us_duty_buffer[i * 3] = (sine[(i+80)%120]); 
 g_us_duty_buffer[i * 3 + 1] = (sine[(i+40)%120/2]); 
 g_us_duty_buffer[i * 3 + 2] = (sine[i]);// signal 1

or somthing with the DMA controller ...

I actually dont understand exactly how this for loop works ..