1 Reply Latest reply on Mar 1, 2018 3:56 AM by srdr

    FX3 Pktend Issues Slave FIFO


      Hi All


      So I'm currently using the SlaveFIFO firmware for the FX3 to send and receive 32 bit data packets from a Master FPGA. Each transaction involves a packet sent from the PC software then once read by the FPGA determines how many 32 Bit words should be returned. As the number of words returned is variable, I have been using Pktend to reduce the latency in the over all transaction, and this is where my problem lies (my buffer size is 16k and only 1 DMA buffer).


      If in the first transaction the PC software requests a set amount of words, lets say 40, the FIFO transaction will work fine. However if in the next transaction the PC software requests any more words than previously requested, like 41, then the transaction will fail, and Xferdata will return false to the Bulk In Endpoint. So far I've tracked it down to the FX3 firmware, whether its in the GPIF or actual firmware I'm unsure.


      Please let me know if I can provide any other helpful information


      Kind Regards