thejayman77
4358bc328b
The four-bank tex_mem split (27dfd0b) closed the -0.370 EMIF drain write-address fanout but the owner GUI fit showed the fitter SCATTERED the banks, pushing the DESIGN-clock sampler read cone (ras_v0_x -> perspective-UV -> texel addr -> tex_mem portbaddr, the design's fundamental ~40ns critical path) to -2.208 ns. Net worse. Codex's call (Option 1 + honest write-side multicycle), implemented: - Restore the MONOLITHIC 65536x32 tex_mem, recovering the clean 25 MHz read-cone placement. Sampler/read-address path stays fully timed (Ch439g); nothing about it is relaxed. - Make the EMIF drain write genuinely two-cycle: new F_SETTLE state between F_DRAIN and F_WRITE. drain_idx_q/drain_word_q are loaded in F_DRAIN, HELD unchanged through F_SETTLE (the load block gates on F_DRAIN), and the RAM write + CRC happen at the later F_WRITE edge. - SDC: fail-closed 2-cycle-setup / 1-cycle-hold multicycle from ONLY u_texcache|drain_idx_q[*] to tex_mem (a 6.45 ns EMIF window for the drain write-address). Scoped -from the drain regs, so the sampler read path (different launch regs) is untouched. HALTs if tex_mem is present but drain_idx_q renamed. The AW buffer (gs_axi_aw_regbuf) and the tile-CDC max-skew 2.5 relax from27dfd0bare KEPT unchanged (both closed their families in the fit). Verified: tb_gs_texture_cache (monolithic + F_SETTLE, distinct-per-byte- lane + full-word, 0 errors), aw/w regbuf, texture_psmt8_clut, scanout_diag, ps2_hps_bridge, and the complete f52 replay BYTE-IDENTICAL (Z 0/307200, COLOR 0/245760). No Quartus/board/push from here. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
retroDE_ps2 Planning Docs
This directory is the working design scaffold for the PS2 core.
Purpose:
- define the intended repository shape before RTL lands,
- define subsystem boundaries before implementation choices harden,
- document what each block owns, what crosses the boundary, and how we will validate it.
Recommended reading order:
- repo_layout.md
- phase0_checklist.md
- contracts/README.md
- stub_module_plan.md
- wave2_dma_gif_plan.md
- wave25_memory_backed_dma_plan.md
- wave26_multi_beat_dma_plan.md
Relationship to references/:
references/is the research library.docs/is the project-definition layer.
Rule of thumb:
- If a file explains PS2 hardware as it exists, it belongs under
references/. - If a file explains how
retroDE_ps2intends to model, partition, or validate that hardware, it belongs underdocs/.