EDMA3 Preemption

Maurizio Borsari

Other Parts Discussed in Thread: PROFIBUS, AM3359

Hi all.

In my application (AM3359 + CCS 6.0.0.00190 + SYS-BIOS 6.40.03.39), some devices (ethernet, profibus, mmc, fpga) use EDMA3 to transfer data from some areas to other memory addresses (DDR3).

FPGA needs to complete the EDMA transfer as soon as possible and should preempt an EDMA transfer eventually already running.

Is it possible?

Thank you very much

Best Regards

over 10 years ago

0 ScottG over 10 years ago

TI__Mastermind 26780 points

Maurizio,

I’m not an expert on this… but yes, I think this is possible, by setting appropriate transfer queue priorities.

There is mention of setting queue priority mappings here: http://processors.wiki.ti.com/index.php/AM335x_EDMA_Driver's_Guide#How_to_change_various_other_global_settings

Also some description of priorities here: http://processors.wiki.ti.com/index.php/EDMA3

And, for a different device, there is description of using priorities in this user’s guide: http://www.ti.com/lit/ug/spru966c/spru966c.pdf. See section 3.4.5.2, which discusses breaking up large transfers to avoid starving other transfers at the same priority level.

Scott

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EDMA3 Preemption