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Honored Contributor
Honored ContributorNIOS II 32 bit data master -> Avalon MM PCIe 64 bit TX slave
I had a system working where the DMA controller ( 64 bit ) was reading and writing to the TX port of the PCIe TX port .
I now have a situation where I want the NIOS II data master ( 32 bit ) to read and write the TX port of the PCIe IP to get to system memory via the PCIe link. Writes seem to go nowhere and reads hand. I believe the fabric should take care of the 32 -64 bit data width mismatch but not sure. Also not sure exactly how to make the NIOS II read or write .. I have an int pointer that I am making *ptr references via where ptr = the QSYS address of the TX port. The TX port has 2 mappings or 4k byte blocks . I could try getting the NIOS to set up the DMA transfer to see if that works better but really want the NIOS II to make references to system memory via the PCIe link. Also , the QSYS says that address bit 31 must be '0' ... for NIOS ,... is there a reasone for that ? Thanks in advance, Bob.
