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EXTERNAL PORT DMA OPERATION

Question asked by R.MISHRA on Oct 30, 2009
Latest reply on Nov 3, 2009 by jeyanthi.jegadeesan

We are using  ADSP 368 SHARC processor and VisualDSP++ 5.0. We are transferring data from external memory to internal memory through DMA Channel 1, The DMA register initialization are as below -

 

 

 

*(volatile int *)IIEP0 =   data;              // data is declare as a int array in the code
  
*(volatile int *)IMEP0 =  1;
  
*(volatile int *)ICEP0 =  64;
  
*(volatile int *)EIEP0 =  (volatile unsigned int *)0x04F82000;                  // address for external momory (fifo)
           
*(volatile int *)EMEP0 =  0;                        // since our external memory is a fifo, so external modifier is zero.
    
*(volatile int *)EBEP0 =  (volatile unsigned int *)0x04F82000;

 

 

My DMA Operation is happening, After examining the internal memory data, I found that each word is repeated twice e.g. 0th and 1st element contains same data, 2nd and 3rd element contains same data  value. If I do this data transfer without DMA mode the data word is coming correctly. External BUS with is set for 16bit.

 

Please suggest.

 

Thanks in Advance.

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