TMS320F280049: HRPWM link and shadow doubt

Jordan Zhou

Genius 9340 points

Part Number: TMS320F280049

Hi, One

There's one doubt about HRPWM.

PWM5 and PWM6 are used:

1) High resolution, CMPA, CMPB, TBPRD

2) PWM6 is linked to PWM5 with CMPA, CMPB, TBPRD and GLDCTL2.

3) PWM5 sends SYNC to PWM6

The doubt are:

1) PWM5 global load is used, does PWM6 need to use?

2) PWM6 registers are linked to PWM5. At the moment PWM5 CMPA changed, when will PWM6 CMPA be changed? By shadow, or immediately?

3) Is there any restriction on these kind of configuration? We found that, when global load is used, PWM6A sometimes doesn't work well, but PWM6B can work well.

Thanks a lot.

Br, Jordan

over 4 years ago

0 Nima Eskandari over 4 years ago

TI__Guru 51940 points

1) I dont believe thats a requirement.

2) I think your CMPA for the slave PWM on the LINK should change as soon as the master of the LINK's register changes.

I am adding Bharathi to comment on this.

Nima

0 Nima Eskandari over 4 years ago in reply to Nima Eskandari

TI__Guru 51940 points

B SUBRAHMANYAM can you confirm?

0 Jordan Zhou over 4 years ago in reply to Nima Eskandari

TI__Genius 9340 points

Any feedback?

Thanks a lot.

Br, Jordan

0 Nima Eskandari over 4 years ago in reply to Jordan Zhou

TI__Guru 51940 points

I will ping Bharathi to confirm.

0 Nima Eskandari over 4 years ago in reply to Nima Eskandari

TI__Guru 51940 points

Link mechanism:

When registers are linked, one write updates all registers simultaneously.

Global load:

load happens when the corresponding shadow to active load pulse occurs, not immediately.

This is different from Link scheme above.

Nima

0 Jordan Zhou over 4 years ago in reply to Nima Eskandari

TI__Genius 9340 points

Thanks Nima.

Let me clarify my understanding:

When registers are linked, one write updates all registers simultaneously.

Doubt: it will update linked active registers or shadow registers, immediately?

If updating active registers, we don't need to use global load, is this right? As, master PWM registers are shadowed, all of the registers are loaded at the same point. And at the same time, slave PWM registers are linked and updated. So slave PWM doesn't need global load.

Br, Jordan

0 Nima Eskandari over 4 years ago in reply to Jordan Zhou

TI__Guru 51940 points

Jordan,

After our email chain, any item left on this request?

Nima

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TMS320F280049: HRPWM link and shadow doubt