EDMA Source Index overzise:0xffff

Dear Guys,

Thanks your help in advance.

Now I met one question about EDMA transfer data as follows.

I want to transfer one whole column pixels from external memory image (size: 32*98304(R*C) )to internal memory,every pixels takes up2 bytes.

I set the following parameters for EDMA:

config.opt = 0x00100004 | (Inttcc<<12); //0x00100004
config.acnt = 2;
config.bcnt = 32;
config.srcbidx = 98304*2;
config.dstbidx = 2;
config.link = 0xffff;
config.bcntrld = 0;
config.srccidx = 0;
config.dstcidx = 0;
config.ccnt = 1;

The marked statement is source index,the value:98304*2= 0x30000,the value takes up 18 bits,which is larger than the bits of EDMA index register(16 bits):SRCBIDX.

How to solve this problem for DMA data transimission?

Platform: DM6446
DSP Core: C64+
ARM Core: ARM9

Thanks a gain

BRS,
Meng Start a New Thread

Mile-

I didn't see that you an answer, so let me take a stab.

> Thanks your help in advance.
>
> Now I met one question about EDMA transfer data as follows.
>
> I want to transfer one whole column pixels from external memory image (size: 32*98304(R*C) )to internal memory,every
> pixels takes up2 bytes.
>
> I set the following parameters for EDMA:
>
> config.opt = 0x00100004 | (Inttcc<<12); //0x00100004
> config.acnt = 2;
> config.bcnt = 32;
> config.srcbidx = 98304*2;
> config.dstbidx = 2;
> config.link = 0xffff;
> config.bcntrld = 0;
> config.srccidx = 0;
> config.dstcidx = 0;
> config.ccnt = 1;
>
> The marked statement is source index,the value:98304*2= 0x30000,the value takes up 18 bits,which is larger than the
> bits of EDMA index register(16 bits):SRCBIDX.
>
> How to solve this problem for DMA data transimission?
>
> Platform: DM6446
> DSP Core: C64+
> ARM Core: ARM9

I believe you will need to do two (2) EDMA transfers, possibly by "chaining" the second to the first so that it
happens automatically, without program code intervention. This is an often-discussed issue with C64x+ DMA... if you
search e2e.ti.com and dsprelated.com for

"transfer size" chaining

"transfer size" linking

you can find some threads.

-Jeff

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