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Trouble with DMA

Started by Jean Viljoen October 9, 2002
Dear group

I am using the C5402DSK and AIC10 EVM populated with 8 CODECS. I am using CCS
1.21 with XDS510PP JTAG emulator. To transfer data between CODECS and DSP an
can use either DMA, or interrupts and then transmit over MCBSP.

I find that when I use the DMA, I need to turn the power off to the DSK/EVM
everytime I want to reload a new program, else it hangs in the init. code of the
AIC EVM. This implies that I need to shut down CCS everytime before I can
reload my program. This takes up vasts amounts of time during development.
Does anyone have a pointer here? When I service the CODECS with interrupts
and MCBSP, everything works fine.

Jean Viljoen
Development Engineer

Azoteq (Pty) Ltd
Tel: +27 21 863 0033
Fax: +27 21 863 1512



When you reset the DMA, you will need to wait for at
least a FULL buffer time before you re-init the DMA
control registers. This is to ensure the DMA sequence
to settle down from previous operations.

Try this sequence:

RESET McBsp
RESET DMA
WAIT for DMA buffer time
INIT McBsp
INIT DMA

The reason it works after you power cycle the board
because the DMA is completly IDLE after power up.

Ben
--- Jean Viljoen <> wrote:
> Dear group
>
> I am using the C5402DSK and AIC10 EVM populated with
> 8 CODECS. I am using CCS 1.21 with XDS510PP JTAG
> emulator. To transfer data between CODECS and DSP
> an can use either DMA, or interrupts and then
> transmit over MCBSP.
>
> I find that when I use the DMA, I need to turn the
> power off to the DSK/EVM everytime I want to reload
> a new program, else it hangs in the init. code of
> the AIC EVM. This implies that I need to shut down
> CCS everytime before I can reload my program. This
> takes up vasts amounts of time during development.
> Does anyone have a pointer here? When I service
> the CODECS with interrupts and MCBSP, everything
> works fine.
>
> Jean Viljoen
> Development Engineer
>
> Azoteq (Pty) Ltd
> Tel: +27 21 863 0033
> Fax: +27 21 863 1512 >
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