Re: When do i need to allocate DMA buffer

2009-01-14 Thread Misbahullah Khan
 Hi Showair , >> Note that my target is to transfer data from memory location to another >>memory location & it will be an overhead if i copy the data from the >>src to >>the DMA buffer then from the DMA buffer to the Destination. >>isn't there any other way to avoid using that DMA buffer & to co

Re: When do i need to allocate DMA buffer

2009-01-13 Thread wael showair
1. so my question is: is there any difference between the DMA engine & the DMA controller? 2. i have read the following section in my reference manual: "The MPC8555E DMA engine is capable of transferring blocks of data from any legal address range to any other legal address range. Therefore, it ca

Re: When do i need to allocate DMA buffer

2009-01-12 Thread sjoy...@wanadoo.fr
Hi Wael, 1. The DMA engine source and destination registers are based on physical memory addresses, whatever is the bus connected on, thus you need to provide it physical addresses. It looks like you are a bit confused about the terminology "DMA buffer": a DMA buffer is either the source and/or de