Help generating DDR3 Verilog module for Digilent NexysVideo Artix-7 FPGA

[tambewilliam]

I have had no luck generating a working DDR3 Verilog module for Digilent NexysVideo Artix-7 FPGA using:

{
    # General ------------------------------------------------------------------
    "speedgrade": -1,      # FPGA speedgrade
    "cpu":        "None",  # CPU type (ex vexriscv, serv, None)
    "memtype":    "DDR3",  # DRAM type

    # PHY ----------------------------------------------------------------------
    "cmd_latency":     0,             # Command additional latency
    "sdram_module":    "MT41K256M16", # SDRAM modules of the board or SO-DIMM
    "sdram_module_nb": 2,             # Number of byte groups
    "sdram_rank_nb":   1,             # Number of ranks
    "sdram_phy":       "A7DDRPHY",    # Type of FPGA PHY

    # Electrical ---------------------------------------------------------------
    "rtt_nom": "60ohm", # Nominal termination
    "rtt_wr":  "60ohm", # Write termination
    "ron":     "34ohm", # Output driver impedance

    # Frequency ----------------------------------------------------------------
    "input_clk_freq":   100e6, # Input clock frequency
    "sys_clk_freq":     100e6, # System clock frequency (DDR_clk = 4 x sys_clk)
    "iodelay_clk_freq": 200e6, # IODELAYs reference clock frequency

    # Core ---------------------------------------------------------------------
    "cmd_buffer_depth": 16, # Depth of the command buffer

    # User Ports ---------------------------------------------------------------
    "user_ports": {
        "wishbone_0" : {
            "type": "wishbone",
        },
    },
}

The generated module gets successfully initialized through its wbctrl interface, but transactions through its user_portwishbone interface never get acknowledged.

Find attached in litedram_nexysvideo.tar.gz following generated files using litedram/gen.py:

build
 |-gateware
 | |-litedram_core.xdc
 | |-litedram_core.v
 | |-litedram_core.tcl
 |-software
 | |-include
 | | |-generated
 | | | |-sdram_phy.h
 | | | |-soc.h
 | | | |-git.h
 | | | |-csr.h
 | | | |-mem.h

Could anyone verify that a module that uses wishbone and generated for Digilent NexysVideo Artix-7 FPGA using litedram/gen.py works ?

[tambewilliam]

@enjoy-digital , I was able to generate a working verilog module that uses wishbone after following revert: git checkout bd80053ebf078a65f7c4614fb110fc1905166d4e~ litedram/frontend/wishbone.py

[enjoy-digital]

@tambewilliam: Thanks for the feedback. I reopen this since will look at it.

[shingarov]

Has this ever been fixed? According to https://github.com/antonblanchard/microwatt/issues/363 the current master works on NexysVideo. Perhaps only the issue needs closing? I verified today and memtest fails on Genesys2 for me.