PSoC5LP DMA interrupt Problem

[Anonymous]

Hi 

   

I need to transfer parallel data using DMA and GPIO. But I have a problem. 

   

I looked at the examples given here.

   

http://www.cypress.com/comment/405831#comment-405831

   

This application is working. I tried it on my CY8KIT-50 Psoc5lp Development kit. 

   

In the given application, the interrupt occurs after all the data has been transferred. But I need to generate a clock signal after each transfer data of the DMA. For example, If the DMA transfer size is 1024 Bytes, I need 1024 interrupt. Because I need to generate a clock signal after writing data to the GPIO.

   

How can I do that?

   

Thanks.

[Bob_Marlowe · Accepted solution]

Set the bytes per burst to one (1) and re-chain the TD

       

Bob

[Anonymous]

Hi bob,

   

Can you explain a little more? I don't understand how to do it.

[himam_31]

Hello,

   

With the current DMA implementation you can generate interrupt only after completion of a TD. However you can have a single TD chained. And now you will have to use a nested DMA approach. ie, you need to have another DMA channel which will change the source address of the main DMA.You modify the source address of the main TD 1024 times.This is not a straight forward implementation.

   

Thanks,

   

Hima