Question about McBsp's DMA configuration

Hi all,

     In my applicaton,    I sample data via Mcbsp and DMA,   2 channels on Mcbsp RX , 16 word/ channel,    data is stored  in Uint16 A[2048] as following
A[0]  --ch1
A[1] -- ch2
A[2]  --ch1
A[3] - ch2
....
A[2046]  -- ch1
A[2047 ---ch2

DMA configuration code  is

  // configure burst
      DMACH2BurstConfig(0, 0, 0);
      // DmaRegs.CH2.BURST_SIZE.all = 0;        // 1 word/burst
      // DmaRegs.CH2.SRC_BURST_STEP = 0;        // no effect when using 1 word/burst
      // DmaRegs.CH2.DST_BURST_STEP = 0;        // no effect when using 1 word/burst

      // configure transfer
      DMACH2TransferConfig((Uint16)2048 -1, 0, 1);
      // DmaRegs.CH2.TRANSFER_SIZE = (Uint16)MCBSPA_RDMA_DATASIZE -1;        // Interrupt every 127 bursts/transfer
      // DmaRegs.CH2.SRC_TRANSFER_STEP = 0;    // Don't move source address
      // DmaRegs.CH2.DST_TRANSFER_STEP = 1;    // Move to next word in buffer after each word in a burst

      // configure address
      DMACH2AddrConfig((Uint16*)(&A[0]),&McbspaRegs.DRR1.all);
      // DmaRegs.CH2.SRC_ADDR_SHADOW = (Uint32) &McbspaRegs.DRR1.all;            // Start address = McBSPA DRR
      // DmaRegs.CH2.SRC_BEG_ADDR_SHADOW = (Uint32) &McbspaRegs.DRR1.all;        // Not needed unless using wrap function
      // DmaRegs.CH2.DST_ADDR_SHADOW = (Uint32) &rdata[0];        // Start address = Receive buffer (for McBSP-A)
      // DmaRegs.CH2.DST_BEG_ADDR_SHADOW = (Uint32) &rdata[0];    // Not needed unless using wrap function

      // configure wrap
      DMACH2WrapConfig(0xFFFF, 0, 0xFFFF, 0);
      // DmaRegs.CH2.DST_WRAP_SIZE = 0xFFFF;        // Put to maximum - don't want destination wrap
      // DmaRegs.CH2.SRC_WRAP_SIZE = 0xFFFF;        // Put to maximum - don't want source wrap
     // configure mode
      DMACH2ModeConfig((Uint16)DMA_MREVTA, 1, 0, 0, 0, 0, 0,SIXTEEN_BIT, 1,1);


Now i want data to  be stored as

ch1: A[0]~A[1023
ch2: A[1024] ~A[2047]

how to configure DMA? thanks in advance.