Double buffered EDMA transfer for Left/Right McASP data

Sherry,

Please see the EDMA3 User Guide and look at the Data Sorting Example that is included in section 3. Once your ping or pong buffer has filled with the interleaved L/R samples, you can then use the Data Sorting technique to split the data into separate L and R buffers are you are trying to do.

Regards,
RandyP

Thank you for a giving a great head start. Looking at section 3.3, it seems that for my application it should be reduced to the following diagram

Now, in the example of Data sorting, Destination address is shown as 1180 0000h on Page 62 of sprugp9b.pdf. If I have Left and Right buffer each of size 4096.( each element is 32 bit and an array of 4096 elements).
Then my Left channel buffer is located in address 1180 0000h. Should my right buffer be starting at 1180 4000h ???
Rephrasing my question as, Are the memory addresses in this diagram ascending horizontally?
If not, then I think this sorting is orthogonal to what I need.

This is what my buffer definitions are like

#define BUFFSIZE 256		//Left and Right buffer size = BUFFSIZE/2
#define BUFFCOUNT	BUFFSIZE*4
#define DATA_SIZE (BUFFSIZE/2)
typedef struct rcv_data_buffer
{
	int32_t left[DATA_SIZE]; 
	int32_t right[DATA_SIZE]; //right buffer will be adjacent to left buffer in the memory location
} RCV_DATA_BUFFER;


typedef struct xmt_data_buffer
{
	int32_t pingL[DATA_SIZE]; //pointer will be used to point to this location
	int32_t pingR[DATA_SIZE]; //right ping will be adjacent to left ping
	int32_t pongL[DATA_SIZE]; //another pointer will be used to point to this location
	int32_t pongR[DATA_SIZE]; //right pong will be adjacent to left pong

} XMT_DATA_BUFFER;

This is how I picture the memory space JUST for receive buffer for ping (in pingPong)

My parameters for receiving the I2S data stream (32 bit) are defined in paRAM set as follows:
ACNT = 4 (4 bytes, 32 bit words)

BCNT = 2 (number of channels)

CCNT= BUFFSIZE/2 (number of frames received)

The source is MCASP sending 32-bit words. These words are read from the same location, hence SRCBIDX = SRCCIDX = 0.
Destination is my received buffer array where I want the data to be written (and sorted simultaneously). The first half of buffer has to be left channel data and second half is right channel data.
Hence in the struct definition above, L/R are defined next to each other so they occupy memory space just after one another. Now, the SRCBIDX has been defined such that, after writing first Left channel sample (L0), the B-index jumps to later half of the buffer array and writes first right channel sample (R0). After writing R0, the first frame is completed. So the DSTCIDX has a negative value, jumping back to upper half of the buffer array and +4 so that it writes a new frame L1, without overwriting L0. 
Please correct me if this concept won't work.

Hello,

I am back to working on this now. 

Reload field is 000

If a negative value for Destination C Index is required, for example, if:
BUFFCOUNT = 512,
WIDTH = 4.
Then according to the picture above for DSTCIDX, my result should be negative number and 2's complement of -252.
Is that correct?
I am getting the following warning for DSTCIDX:
#69-D integer conversion resulted in a change of sign