omapl138 upp dma problem

Hi,

We are using UPP to send data from FPGA to DSP running on 40 MHz. It is 100K 4-byte data, thus we are storing this data at external DDR2.

In DSP, we DMA the data to external DDR2. And both ARM and DSP have access to the external DDR2.

We have found that when ARM is running some code (example like below) that is memory extensive, the UPP DMA to external DDR2 will fail with UOR (Underrun or Overflow) event, some data from FPGA is lost.

We guess this could be due to the bus contention between ARM and UPP DMA. Thus, to workaround this, we use DSP L2 RAM as the temporary destination for DMA, and then move the data from DSP L2 RAM to external DDR2 using memcpy.

I asking is there any better alternative than this workaround as we would like to increase the data size from 100K to 1M. And ideally we want to DMA the 1M data to the external DDR2 directly without having to go thorugh the L2 RAM first.

bool testMemCpy( void )

{

unit32 *src = new uint32[2600];

unit32 *dest = new uint32[2600];

memcpy( dest, src, 2600 );

delete [] src;

delete [] dest;

return true;

}

We

rgds,

kc Wong