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SSP & DMA issue in LPC4357 microcontroller...

Question asked by Muralidhar M on Jun 22, 2016
Latest reply on Jul 26, 2016 by Carlos_Mendoza

I had interfaced the LPC812(Slave) to LPC4357(Master) microcontroller through SSP interface.

The SSP at LPC4357 is controlled through DMA. The configurations at LPC4357 are as follows,

SSP :

Frame length : 8-bit,

Communication : SPI, Master

Mode : 1 (CPOL : 0, CPH : 1)

 

DMA:

Rx & Tx channels

Source & destination burst sizes : 1 byte

Source & destination data widths : 1 byte,

     Rx channel : (Channel 0)

     Mode : Peripheral to memory

     Data flow control : DMA control

     Terminal Count interrupt : enabled

     Tx channel : (Channel 1)

     Mode : Memory to peripheral

     Data flow control : DMA control

     Terminal Count interrupt : disabled

When I performed data transfers , it is working for few transfers well as I expected. But some times, I never got the TC interrupt, when go through debugging, I found that, the ROR flag in Raw interrupt status if SSP is getting high & Tx channel of DMA completed its transfer but the Rx channel of DMA not at completed its transfer ever... So, I am not getting the TC interrupt from Rx channel of DMA. This occurring very frequently...

Please help me on this...Its very.. very.. urgent...

Thanks in advance...

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