Not enough throughput while testing GPIFtoUSB on FX3 | Cypress Semiconductor
Not enough throughput while testing GPIFtoUSB on FX3
I have two issues I want to get some explanation about:
1) I'm testing the stream IN firmware on my FX3 Super Speed Explorer Kit with an FPGA Cyclone IV. The test works perfectly while testing with USB 2.0 port but when using a USB 3.0 port there are only few packets that pass the test and it rapidly get failures after that. I am aware that the buffer' sizes are bigger but for me it shouldn't be a problem since we are using USB 3.0 which is adapted to that.
2) To verify the throughput I'm working with, I did a test with the GPIFtoUSB firmware like mentioned in the AN86947 . I changed the values of "burst length", "Size of DMA Buffer" and "number of buffers" each time like mentioned in table 8 in the AN86947 but I never got a throughput bigger than 185000KB/s ( even with 4 buffers !) and I don't seem to understand why knowing that I tested on different USB 3.0 host controllers and OSs ( I tested on Intel® USB 3.0eXtensible Host Controller / Win8 64bit and also on Renesas Electronics USB 3.0 Host Controller / Win7 64bit ).