• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 98 subscribers
  • Views 129 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Issue understanding EDMA

balasubramanian Vaidhyanathan16311
Prodigy 140 points

HI

 

   i have used EDMA2. before and it was pretty easy. I am a little confused on EDMA3. Let me explain what I have understood and if somebody can chip in and clear some doubts I have it would be great. I understand that there are 256 PaRam entries and 64 DMA channels. Each DMA channel has a DCHMAP register which tells which of the PaRam that channel is configured with. Now what I do not understand is the concept called shadow register. It looks complicated when i read the manual for EDMA controller. Can someone tell me in simple terms the importance of this shadow region and registers/...

 

 

regards

bala

  • 0
    TI__Guru* 84110 points

    EDMA3 Shadow Regions/Registers are definitely not easy to understand. I have not yet figured out an easy way to explain how to use them and more importantly why to use them, but they can be very useful for multi-core DSPs like the C6474.

    But since some of your other postings involved the C6455, I will assume this is what you are using for this posting, too. And for a single-core DSP like the C6455, there is only a very specialized and limited value to using the Shadow Regions. I recommend you stay with the "REGION_GLOBAL" for this device.

    In simple terms, the shadow regions allow you to allocate DMA and QDMA channels to be used exclusively by willing software objects. It is not an enforced exclusivity, so each software object must only work with the Region that has been assigned to it.