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EDMA +delay

Started by Markus July 13, 2005
Hi,

I work with a TI DSP (C6713). I read and write data with MCBSP and EDMA
(Ping Pong buffering). Now my question is how long will it take to send
one Sample from the Input to the Output. The Samplefreq is 48KHz and
the Buffersize 128Samples.
I am not sure if the right answer is 128/48000=2.66ms or
2*128/48000=5.33ms.

Thanks

Markus wrote:
> Hi, > > I work with a TI DSP (C6713). I read and write data with MCBSP and EDMA > (Ping Pong buffering). Now my question is how long will it take to send > one Sample from the Input to the Output. The Samplefreq is 48KHz and > the Buffersize 128Samples.
to accquire 128 samples to your input buffer it takes you 128/48000=2.66 ms (this is the t here) ... then you switch the buffer and immediately start playing the buffer? let's draw a picture ---------------> time tttttttt rec 01234567 play 01234567 and you want to know the time from sample 3 beeing recorded to beeing played back? that should be 2.66 ms as well I would call that latency from input to output In case you want to do any processing in between you would need 3 buffers and get more latency ... I got a pile of white paper and a pen at my desk - in any case I'm not sure I start drawing. I take white paper because some of them could end up in a folder for documentation ... bye, Michael