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Using cache and SDMA

Question asked by Mar Kon on Dec 7, 2017
Latest reply on Dec 15, 2017 by Mar Kon

Hi, everybody. I have system based on iMX6, FreeRTOS. I need copy table from one point of memory to another. I use for this task SDMA. Memory attribute is write-back cacheable. Before starting copy by SDMA, I clean data cache by MVA to point of coherency and I use DSB to stop CPU to be sure, data are in memory. Then I start copy by SDMA.

My problem is, that one per thousands times, SDMA copies old data.

I don't know, which question is the most suitable.

Why CPU doesn't wait for data would place in memory?

Should be any signal from memory to CPU to inform data are in memory?

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