Altera_Forum
Honored Contributor
Honored ContributorURGENT: Peripheral to Memory DMA Transaction
Hello, may I know how to transfer data from peripheral to memory using DMA? It is quite confusing from memory-to-memory transfer. please help! thanks!
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Altera_ForumHonored Contributor
Honored ContributorI think I know why. Correct me if I am wrong...
1 number = 4 bytes and the length of the DMA is 200, which means 200 bytes. So, the DMA will transfer 200bytes of data (equivalent to 50 numbers only, 200bytes/4bytes = 50). So, DMA will write 0-49 only. Am I right? Besides, how many bits are there in 1 address location? 32bit? What does it mean when SDRAM has 16bit data width, meaning 1 address of SDRAM has 16bit? If the source is 32bit, one fetch of data from the source is 32bit(store in 1 address of the source) but when reach SDRAM which is 16bit, it needs 2 address location to store the 32bit data from source. Am I correct? update: seem like the transfer has some problem. in the source, there is 200 numbers, but after transfer to peripheral then to memory again, the number is less than 200.
