AN2367

Example of C call

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Appendix B

Example of C call

ulong DMACHandleRxPkt(void* ppkt, ushort size)

{

__DMA_DSCR_Base

*pDescr;

dmacEthernetif

*ptDMACIf;

ulong

value;

ptDMACIf = GetDMACContext();

/* Check if the descriptor is owned by the DMA or CPU */

value = (ulong) (ptDMACIf->pDmaRxDscrBase->dmaPackStatus &

DMA_DSCR_RX_STATUS_VALID_MSK);

/* Check for valid mask

*/

if (value == DMA_DSCR_RX_STATUS_VALID_MSK)

{

return (DMAC_NOK);

}

// Get the Rx Descriptor base

pDescr = ptDMACIf->pDmaRxDscrBase;

// Check for validity

if ( (pDescr != NULL)

&& (pDescr->dmaAddr)

)

{

size = ((pDescr->dmaPackStatus & 0x7ff) - 4);

MEMCOPY_L2S_BY4((char *)ppkt, tempRxAry, size);

}

else

return DMAC_NOK;

/* Give the buffer back to DMAC */

pDescr->dmaPackStatus = DMA_DSCR_RX_STATUS_VALID_MSK;

/* Start the receive operation */

DMAC_REG_BIT_SET( ptDMACIf->pRfDMA->dmaRxStart,

DMA_RX_START_FETCH);

// Return no error

return DMAC_OK;

}