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Hi everybody i am working on SHARC ADSP 21060.i want to use multiple DMA channels at the same time. actually i am reading data thru serial port 1 in blocks of 1ms and processing this data. after every 20 ms i need to transfer 1 bit, i get after this processing.these number of bits also need further processing. so i though i will send thses data bits thru other serial port 0 while serial port 1 is continously collecting data. is it possible to activate two dma channels simultaneosly?if yes how can i do it.since there is only one I/O bus that links to sram,hows it possible to make communication using two channels. thanks in advance regds sandeep |
how to activate multiple DMA channels
Started by ●December 14, 2004
Reply by ●December 14, 20042004-12-14
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On Tue, 14 Dec 2004, sandeep kumar wrote: > Hi everybody > i am working on SHARC ADSP 21060.i want to use multiple DMA > channels at the same time. actually i am reading data thru serial > port 1 in blocks of 1ms and processing this data. after every 20 ms i > need to transfer 1 bit, i get after this processing.these number of > bits also need further processing. so i though i will send thses data > bits thru other serial port 0 while serial port 1 is continously > collecting data. > is it possible to activate two dma channels > simultaneosly?if yes how can i do it.since there is only one I/O bus > that links to sram,hows it possible to make communication using two > channels. Howdy Sandeep, Yes, you can have as many dma channels as you want running at once. The trick is to set the priority levels correctly so that when a bus collision occurs, the most important data is transfered first and the less important data is delayed. In my manual this is described in section 6.3.3 "DMA Channel Prioritization" (page 6-25). It says the priority levels are fixed, so make sure your highest priority data is on the lowest dma channel number. I'd think you want to switch things around - collect data on sport 0 and transmit the results on sport 1 to take advantage of the priority scheme. Patience, persistence, truth, Dr. mike |
