Posted on May 17, 2011 at 09:39Hi veryone!Before you start the RX DMA,you should have to allocate a 16-byte region in main memmory,for each DMA transfer.3 words for DMA descriptors,plus 1 word for Packet Status and descriptor VALID bit.In the first three descritor words ,you write the information to be loaded in the : ENET_RXCR,ENET_RXSAR,ENET_RXNDAR.
Do these mean that: when I use the follow codes to init the descritor,it is equal to write the data to the accordingly register directly?
dmaRxDscrBase.dmaAddr = (u32)RxBuff;
/* Initialize RX ENET Status and control */
dmaRxDscrBase.dmaStatCntl = 0x0;
/* Initialize the next descriptor- In our case its single descriptor */
dmaRxDscrBase.dmaNext = (u32)pRXDescrChain;
Best regards!
sunshan
