TMS320F28379D: Synchronizng two DSPs

Milarepa

Part Number: TMS320F28379D

Hi,

We have a power converter which require 48 PWM signals. All these PWMs have to be synchronized. As all 48 PWMs cannot be generated from one DSP, two DSPs are required.

Is it possible to synchronize two DSPs in some way. The switching frequency of the converter is 150 kHz. Can the clock signal from one DSP be sent to other without getting corrupted by noise.

Kindly let me know the best way to synchronize two DSPs.

Thank you.

over 4 years ago

0 Nima Eskandari over 4 years ago

TI__Guru 52040 points

Yes you can sync the two DSP's EPWM modules using the EPWMSYNCO and EPWMSYNCI

0 Milarepa over 4 years ago in reply to Nima Eskandari

Expert 1680 points

Can the EPWMSYNCO signal be generated in some GPIO pin of first DSP and then connected via some wire to some GPIO pin of the other DSP.

Where can i get more details regarding this.

Also , when switching at 150 kHz, wont this signal get corrupted with noise.

0 Nima Eskandari over 4 years ago in reply to Milarepa

TI__Guru 52040 points

EPWMSYNCO, EPWMSYNCI is documented in the TRM. You can use any GPIO with INPUT XBAR5 or 6 for EPWMSYNCI.

For EPWMSYNCO GPIO connection, refer to the PinMux info in the datasheet.

0 Milarepa over 4 years ago in reply to Nima Eskandari

Expert 1680 points

Thank you, I will try out this.

Since the signal we are transferring is of the order of 100 kHz, is it better to use ethernet cable/USB cable for transferring this signal to other DSP, to avoid getting corrupted by noise.

We can migrate to 28388D DSP for ethernet communication.

Kindly let me know your views.

Thank you very much for your replies.

0 Nima Eskandari over 4 years ago in reply to Milarepa

TI__Guru 52040 points

How far are the two board?

0 Milarepa over 4 years ago in reply to Nima Eskandari

Expert 1680 points

The two DSPs are side by side, probably 4-5 inches apart.

0 Nima Eskandari over 4 years ago in reply to Milarepa

TI__Guru 52040 points

You should be okay, have you tested this?

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TMS320F28379D: Synchronizng two DSPs