otpu-ddr4

otpu-ddr4 [status | bist | ecc] [--dev path] [--dimm D]... [--gib G] [--passes N] [--clear]

otpu-ddr4 is the memory bring-up tool for an openTPU board with one LiteDRAM DDR4 core per DIMM (the BCU1525: Virtex UltraScale+ VU9P, four DDR4 DIMMs). After `pip install -e .` in the FeSens/openTPU tree it is installed as a console script (`opentpu.host.ddr4:main`). It can also be invoked as `python -m opentpu.host.ddr4`.Each DIMM d has CSRs in BAR0 at R_DDR4 plus d times DDR4_STRIDE. Each core's CPU (LiteX BIOS) calibrates its DIMM at reset and logs on the UART (DIMM C1's core drives the board's). This command reads and tests what the CSRs reach. The CSR map and PHY settings ship in `opentpu/host/litedram4` (generated from the BCU1525 LiteDRAM tree).The bitstream must be register map 4 with a target whose platform mem is ddr4 and mem-ctrl is litedram. The Verilator board model has no LiteDRAM cores; the command then exits 2. Board channel j equals 2s + c (slice s, channel c) and maps to DIMM C0, C1, C3, C2 in that channel order.status (default) prints STATUS CALIB0 / CALIB1 / ECC_DED, then per DIMM: the core identifier string, a scratch register write/read-back, calibrated (cal_ready or BIOS DFII hardware-control hand-over), ECC enable, and ECC counters. Exit 1 if any selected DIMM fails the scratch check or is not calibrated.ecc prints 64-bit corrected and uncorrectable word counts since the last clear. Exit 1 if any selected DIMM has uncorrectable errors.bist runs each DIMM's built-in self-test over the first --gib GiB (default 1): per pass, random then address data, written then read back. Beats are the 576-bit raw port's, past the ECC, so the check bits are left wrong. The command clears the DRAM-init scratch marker; the next BoardBackend scrubs the DRAM. bist holds the device lock (DMA transport); status and ecc only read registers, like otpu-smi.

status

Per-DIMM identifier, scratch, calibration, and ECC. Default when no subcommand is given.

Write, then read and check, --gib GiB from each selected DIMM's start.

Print ECC counters. --clear zeros them after the read (every DIMM's, not only --dimm).

XDMA device prefix (default `/dev/xdma0`).

DIMM index (repeatable). Default: every DIMM in the bitstream. Unknown indexes exit 2.

With bist: GiB per DIMM from its start (default 1.0).

With bist: passes of random-then-address (default 1).

With ecc: clear counters after printing.

Only a real DDR4 LiteDRAM card: anything else prints `not a DDR4 LiteDRAM card` and exits 2. bist overwrites DRAM and the ECC check bits; chat or serve on that card after a BIST needs a scrub. status and ecc do not take the device lock; bist does, so it will not run beside otpu-chat. The command is installed only via `pip install -e .` in the openTPU tree.

otpu-ddr4 is part of the openTPU host tools (Apache-2.0, FeSens). YPCB-00338 production cards are DDR3 (see otpu-memcal); the BCU1525 target uses one LiteDRAM DDR4 core per DIMM, documented in `docs/bcu1525.md`.

otpu-memcal(1), otpu-diag(1), otpu-smi(1), otpu-setup(1), otpu-selftest(1)

Source code · Documentation