Hi Andrea,
Sorry, I have no idea of the attached file to be erroneously, then make you felt confused.
Let me explain it in details.
As the these figure 1 & figure 1 illuminates, the Memm-to-memory mode doesn't request trigger (Fig 1), then figure 2 has demonstrated the completely process of the Memm-to-memory mode, it works without any peripheral requests.
So you need to trigger the Memm-to-memory transfer via the software instead the original approach.
Hope this is clear.
Fig 1
Fig 2
Have a great day,
Ping
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Hi jeremyzhou thanks for your reply. I tested your code and it is not working.
I think you copied the timer setup from the "timers.c" example, but this is not enough to get the dma example working.
What the example NXP is providing is supposed to do the following:
while(1)
{
- Initialize timer, dma, a source buffer
- At every timer match the dma copy of the source buffer into the destination one should be automatically (read via hardware) triggered by the timer match event.
- Re-initialize the source buffer with random numbers
}
I hope I explained what is going on.
The code you suggest is not working, in-fact nothing is being transfered into the dest buffer: even if the DMA ISR is called, the destination buffer is constantly 0. As you can see in the picture below.
So, may I ask you (or someone in the technical support at NXP) to dig a little further? This chip is as poorly documented as underrated:
Looking forward to hear from the support team.
Andrea
Hi Andrea,
Let me clarify it.
I'm afraid that your purpose can't be achieved as the Memory-to-memory DMA flow mode doesn't support the request trigger (Fig 1). Therefore, you should follow these process to trigger DMA when match even happen.
1).
Initialize timer, dma, a source buffer.
2).
while(1)
{
Output the values of the destination area for checking.
Re-initialize the DMA
}
3).
In the timer's interrupt function, enable the DMA channel (Set the E bit in the Channel configuration registers) which can be implemented via calling the Chip_GPDMA_Transfe().
Fig 1
Hope it helps.
Have a great day,
Ping
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------
Hi Andrea,
Sorry, I have no idea of the attached file to be erroneously, then make you felt confused.
Let me explain it in details.
As the these figure 1 & figure 1 illuminates, the Memm-to-memory mode doesn't request trigger (Fig 1), then figure 2 has demonstrated the completely process of the Memm-to-memory mode, it works without any peripheral requests.
So you need to trigger the Memm-to-memory transfer via the software instead the original approach.
Hope this is clear.
Fig 1
Fig 2
Have a great day,
Ping
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------
