cdma_app.c does not work correctly

[profroyk]

I've been following the Zynq-7000 SoC Embedded Design Tutorial (2023.2) using a Digilent Zybo Z7-20. The cdma-app showed FAIL even though the DMA transfer occurred (I used the Memory inspector to read 0x2000_0000 (the source) and 0x3000_0000 (the destination). I root caused the problem to the buffer compare where it appears that 256 bytes were being compared (Length=64*sizeof(u32)) even though only 64 bytes were transferred in the DMA transfer.

The fix was pretty easy once I figured out so I thought I'd share. The problem was in the SrcPtr and DestPtr declarations. I changed the declarations as shown: // Changed from original code to fix pointer references u8 SrcPtr = SourceAddr; u8 DestPtr= DestAddr; // end changes

Both the source and destination buffers were defined as u8 in the version of the app that I downloaded so now SrcPtr and DestPtr can access the u8 "array".
Roy