thejayman77/retroDE_ps2
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

REVERT REQ_DEPTH to 8192 — 1024 was UNSAFE (Codex audit)

Browse Source 
My REQ_DEPTH=1024 reduction was wrong: I sized it off a 478 peak from a SMALL
scene. The documented full-f52 replay peak is 6,115 (adjacent frame 3,610; even
2,048 clips) — ch439_timing_convergence_prefit.md. The raster cannot backpressure,
so an undersized FIFO SILENTLY DROPS Z-requests -> corrupt frame. The -0.074 fit
was on an invalid (drop-prone) config. Restore 8,192 as the correctness baseline.
The real timing fix is a registered/skid AR-handshake boundary (arbiter s2_arready
combinational -> texcache F_AR), NOT FIFO shrinking. Packaging that for Codex review.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This commit is contained in:
thejayman77
2026-07-21 08:37:39 -04:00
parent 547811e89b
commit 67aa332928
1 changed files with 1 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
rtl/top/de25_nano_psmct32_raster_demo_top.sv
+1 -1
View File
@@ -2376,7 +2376,7 @@ module de25_nano_psmct32_raster_demo_top (
// queued requests. 8K retains 2,077 entries (34%) of
// measured headroom while halving the deep 93-bit FIFO's
// M20K/address-tree footprint at 310 MHz.
.FB_PXW(ZFB_PXW), .FB_H(ZFB_H), .REQ_DEPTH(1024), .COL_DEPTH(128)) u_zc_emit (
.FB_PXW(ZFB_PXW), .FB_H(ZFB_H), .REQ_DEPTH(8192), .COL_DEPTH(128)) u_zc_emit (
.gs_clk(design_clk), .gs_rst_n(core_rst_n), .enable(1'b1),
.g_valid(zc_g_valid), .g_ready(zc_g_ready), .g_x(zc_g_x), .g_y(zc_g_y), .g_zq(zc_g_zq),
.g_zmsk(zc_g_zmsk), .g_ztest(zc_g_ztest), .g_ztst(zc_g_ztst), .g_color(zc_g_color), .g_alpha(zc_g_alpha), .g_be(zc_g_be), .g_scene(zc_g_scene),