NIOS II DMA HAL

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However I do notice that in your test code you use a transfer size of DMA_BUFF_SIZE*2 and in your HAL example you use a size of 1024.[/b]

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Excuse me. In my case it is bad style.

For dirrect DMA registers acsess:

For DMA_BUFF_SIZE*2:# define DMA_BUFF_SIZE (1024*1024+1) // transaction word 16-bit

alt_u16 *buffer=NULL;

buffer = (alt_u16 *)memalign(2, DMA_BUFF_SIZE*2); // allocate memory for DMA_BUFF_SIZE 16-bit words

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IOWR_ALTERA_AVALON_DMA_LENGTH(DMA_SPI_REC_BASE, DMA_BUFF_SIZE*2);

For HAL example:# define DMA_BUFF_BYTESIZE 1024

alt_u16 buffer[DMA_BUFF_BYTESIZE];

alt_dma_rxchan_prepare (rx, &buffer[0], 1024, NULL, NULL);

Memory overwritenn cann&#39;t occur, becouse:

1. In prepare call I request less bytes then allocated for buffer.

2. DMA HAL passed to infinite ISR cycle before call of function Send2Sharc(0xA5); This function initiate the transfer process.