Files
FPGA-Neural/hardware/v2/logs
micheleandClaude Sonnet 5 8ad04987de feat: denser activation packing, real bandwidth ceiling doubled (EXP-0081)
Implements the highest-leverage fix from EXP-0080's bottleneck
analysis: act_tile_fetch.v now packs 2 consecutive tiles per DDR3
burst (even tile low 64 bits, odd tile high 64 bits) instead of 1
tile per burst, halving real DDR3 bytes-per-useful-byte. Timing-safe
by construction: the tile-index select bit is registered at request
time, long before the real DDR3 round-trip completes, never racing
the arriving read data (unlike the runtime part-select pattern
EXP-0079 deliberately avoided).

Re-verified at all 3 levels (isolated engine 8/8, packed_slot.v 9/9
with bit-identical results to EXP-0079, full N=2 system on real DDR3
8/8) -- the real JEDEC trace now shows no half-burst padding, direct
confirmation the fix works in practice, not just in theory.

Also: real device data gathered on this package's I/O bank layout
(only 5 banks total, 14/15/16/34/35) informing the next bandwidth step
(32-bit-wide single controller recommended over a second independent
channel, given the pin/logic cost comparison).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MUG92aM9m68TRc4rG55BcC
2026-09-20 09:55:16 +02:00
..

Formato dei log V2

Regola non negoziabile (docs/v2-description.md §25-29): ogni attività significativa (modifica, simulazione, sintesi, benchmark, decisione, errore) deve essere registrata. Nessun log viene mai sovrascritto o troncato — solo append. Nessun ID esperimento (EXP-XXXX) o decisione (DEC-XXXX) viene mai riutilizzato, anche se il risultato è un FAIL.

File

  • development.log — log principale di sviluppo, un'entry per ogni sessione di lavoro/milestone (creazione file, refactor, avanzamento roadmap).
  • architecture.log — decisioni e note di architettura a grana fine (non scelte finali — quelle vanno in decisions.log — ma esplorazioni, alternative considerate, vincoli scoperti).
  • simulation.log — ogni run di simulazione (Icarus/Verilator): test, vettori, cicli, PASS/FAIL, confronto bit-exact con V1, stall/memory-wait.
  • synthesis.log — ogni run Yosys: LUT/FF/DSP/BRAM, warning, problemi CHECK.
  • timing.log — ogni run nextpnr-ecp5: Fmax, percorso critico, WNS/TNS se disponibili. Fmax "ufficiale" di una configurazione = solo da qui, mai da simulazione o stima.
  • benchmark.log — tabelle di confronto per configurazione (Fmax, MAC/cycle, cycles/neuron, utilization, ecc.), sempre con etichetta THEORETICAL/SIMULATED/SYNTHESIZED/POST-P&R.
  • decisions.log — decisioni architetturali importanti, formato DEC-XXXX (vedi docs/v2-description.md §27).
  • experiments.log — registro principale, un EXP-XXXX per ogni esperimento end-to-end (config → sim/synth/timing → risultato), rimanda a reports/experiments/EXP-XXXX/.
  • errors.log — errori/bug/regressioni incontrati durante lo sviluppo V2 stesso (non i bug V1, già chiusi in hardware/v1/docs/validation/bugs.md).

Campi minimi per entry (§26)

timestamp, experiment_id (se applicabile), git_commit, session/agent,
module, configuration, action, reason, command, result, errors, decision,
next_action

Per synthesis/timing aggiungere: LUT, FF, DSP, BRAM, Fmax, critical path, WNS/TNS. Per simulazione: test, vectors, cycles, PASS/FAIL, bit-exact result, stall cycles, memory wait, utilization.