Commit Graph
2 Commits
Author SHA1 Message Date
micheleandClaude Sonnet 5 cbd16dd727 docs: sync physical/architecture docs with EXP-0081/0082 reality, add 32-bit vs dual-channel analysis
- PHYSICAL_REALIZATION.md: replace stale "1 tile = 1 burst" layout
  description with the real EXP-0081/0082 "2 tiles = 1 burst" convention;
  add EXP-0082 signoff row and history table.
- ARCHITECTURE_ANALYSIS.md: mark §5.1 (denser activation packing) DONE with
  real re-measured numbers (bandwidth ceiling fraction 25%->50%, WNS
  +0.030->+0.068ns); add §5.4, the real device-data-backed comparison of
  32-bit single-channel widening vs a second independent DDR3 channel
  (decided: 32-bit widening, per real DQS/bank pin-conflict analysis);
  update scaling-path recommendation to reflect the user's final directive
  (widen channel -> build DDRManager -> N=2/4/8/16 tests, N=8 target, N=16
  documentary).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MUG92aM9m68TRc4rG55BcC
2026-09-20 10:07:16 +02:00
micheleandClaude Sonnet 5 43a12379a5 feat: MILESTONE - real activation-fetch engine, full N=2 system verified on real DDR3 (EXP-0079)
Closes the last major disclosed functional gap: packed_slot.v's
activation data was read through a combinational stand-in since
EXP-0062. New act_tile_fetch.v reads activation tiles directly from
DDR3 (no on-chip buffering needed, unlike weights -- activation data
has no reuse), sharing each slot's existing ctrl port with its own
weight-prefetch engine. Real memory layout: one full BURST_LEN=8-word
burst per tile, deliberately avoiding any runtime-indexed part-select
given this project's thin P&R timing margin (EXP-0078).

Verified at three levels: act_tile_fetch.v alone (6/6), packed_slot.v
with real preloaded activation data (9/9), and the full N=2 system
against real DDR3 via xsim (8/8, 0 errors) -- the first time this
project's compute path has been verified end-to-end with real DDR3
for both weights and activations.

Retired hardware/v3/rtl/n2_system_top.v and its testbench (pre-DDR3
SDR-placeholder era, fully superseded by n2_system_ddr3_top.v).

Also: docs/PHYSICAL_REALIZATION.md (real pinout/parts/timing/protocol
reference for the physical board) and CLAUDE.md (persistent project
instructions for future Claude Code sessions).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MUG92aM9m68TRc4rG55BcC
2026-09-20 08:13:15 +02:00