# Ch443f board validation

Date: 2026-07-24

Candidate:

- Git commit: `4110846` (`Ch443f timing: preload Z-RMW eviction awaddr at fill`)
- RBF: `retroDE_ps2.ch443f.4110846.core.rbf`
- SHA-256: `59c6372e1cfeba62dccdce860f7ab365255ef32a77c3f7b13909b4c7cff16a87`
- Quartus: 26.1.0 Build 110, Seed 3

Fit acceptance:

- Setup: `+0.068 ns`
- Hold: `0.000 ns`
- Recovery: `+1.080 ns`
- Removal: `+0.003 ns`
- Minimum pulse width: `+0.200 ns`
- RAM: `322 / 358`
- Zero violated paths

Board load:

- Remote candidate hash matched the local artifact.
- `core_loader.sh` reported `Fabric loaded successfully`.
- `fpga0` state: `operating`
- `CORE_ID`: `0x50533200`
- ABI: `0x00000100`
- Board canonical `/home/terasic/cores/retroDE_ps2.core.rbf` was not modified and
  remained SHA-256 `56e45346338907eb6c307320757774ac65efa56dabb644906a5600f5ea73a982`.

Functional replay:

- Complete 311-epoch `sh3_zsrt139f52` replay finished `DONE rc=0`.
- Every epoch passed texture CRC, drain, and zero-fragment-drop gates.
- Framebuffer SHA-256:
  `d0047677371a0f6e4e319458926f604a8599c92baaf34d09b8e1fd452e31662b`.
- The board framebuffer was byte-identical to the retained Ch443e/golden
  framebuffer.

Scanout diagnostic:

- 60 samples at 50 ms spacing plus 60 samples at non-harmonic 7 ms spacing.
- All 120 observations were identical:
  - `0x02C = 0x000000D1`: scan-error bit 5 clear.
  - `0x120 = 0x00000018`: qualified valid=0, underflow=0, read-error=0,
    live `pmax=0`.
  - `0x124 = 0x00408020`: stale snapshot payload; ignored because valid=0.
- No fifth line buffer is justified. The Ch443e four-buffer/lead-2 change fixed
  the real lookahead starvation; the remaining pre-Ch443f indication was caused
  by the raw readiness CDC / synchronization transient.

Disposition:

- Ch443f is timing-clean, renderer-correct, and scanout-clean on silicon.
- Board left running the Ch443f candidate.
- Canonical artifact left untouched pending an explicit promotion instruction.