Check your system Clock frequency. you use 32-bit so enable the SysClk400 in CyU3PDeviceInit.
Thank you. It works now.
How long is the latency from INTR_CPU to CyU3PDmaMultiChannelCommitBuffer? With 100MHz and 16KB buffer, one would expect to interrupt to hit & commit every 40us. Is the CPU fast enough to add header in that 20000 cycles?