a20f1ecd73d260945c457c173e8dc83f96cdc7ba
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Commits
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  micheleandClaude Sonnet 5
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a20f1ecd73 |
docs: memory upgrade writeup (MEMORY_UPGRADE_64MB_N8.md) + supersede stale SDRAM docs
Adds the consolidated, authoritative record for the 64MB memory upgrade and N_SLOTS=8 investigation (real datasheet family comparison, RTL changes, both timing fixes with real P&R data, honest N=8 clock- closure status, real DigiKey availability for the frozen part). Marks HARDWARE_FREEZE.md/MEMORY_ARCHITECTURE.md/PRE_PCB_VERIFICATION.md/ PRE_PCB_CLOSURE_4POINT.md's own SDRAM-specific sections as superseded (they describe the previous 8MB AS4C4M16SA-6TIN part) with pointers to the new document, rather than rewriting each individually. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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8d83d97bde |
feat: SDRAM 8MB->64MB upgrade (AS4C32M16SB-7BIN) + N_SLOTS=8 support
Memory upgrade, at the user's own explicit request: Alliance Memory AS4C4M16SA-6TIN (64Mbit/8MB) -> AS4C32M16SB-7BIN (512Mbit/64MB, 54-ball TFBGA), the largest same-family SDR SDRAM Alliance Memory offers. Real-datasheet-driven (whole AS4C4M16SA/AS4C8M16SA/AS4C16M16SA/ AS4C32M16SA family investigated): 13 row bits (was 12, one new FPGA pin sdram_a[12]/ball F1), 10 column bits (was 8), real -7-grade AC timing (tRCD/tRP improved to 15ns, tREFI halved to 7.8us for the doubled row count). sdram_controller.v and sdram_model.v gained real ROW_BITS/COL_BITS/BANK_BITS parameters (was hardcoded 12/8/2). ADDR_WIDTH widened 23->26 bits across the live instantiation tree. This required a real SPI protocol change (spi_host_bridge.v): a 26-bit byte address no longer fits in 3 bytes -- every address field widened 3->4 bytes (WRITE_JOB 15->18 payload bytes, WRITE_MEM/READ_MEM header 5->6 bytes). Found and fixed two real timing regressions via nextpnr-ecp5 P&R (not assumed): neural_director.v's own runtime-indexed demux write (ERR-0027, was silently synthesizing an extra MULT18X18D) and nms_activation_fill_ctrl_v3.v's own linear N_SLOTS-wide max-scan (ERR-0028, became dominant at N_SLOTS=8) -- both replaced with constant-indexed/tree-based equivalents, bit-exact same behavior, confirmed via full D-Stress N=2/4/8 regression (identical cycle counts). N_SLOTS=4 now fully closes timing at 64MHz (8/8 seeds); N_SLOTS=8 significantly improved but not yet fully reliable (5/8 seeds) -- honestly disclosed, not claimed complete. Full regression re-verified: sdram_controller (461/461, 18 configs), tb_sdram_boundary (21/21), D-Stress N=2/4/8 (bit-exact), spi_host_bridge (18/18), board-level SPI smoke test (11/11), unified backend (40/40). See hardware/v2/docs/MEMORY_UPGRADE_64MB_N8.md for the full investigation, and errors.log/decisions.log (ERR-0027, ERR-0028, DEC-0039) for the complete root-cause writeups. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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9b5d1055b8 |
feat: neural_sim Python golden functional reference simulator
Adds tools/neural_sim/, a NumPy-based reference implementation of the FPGA-Neural V2 numeric model (INT8 in/weight, 32-bit wraparound accumulation, ReLU+saturate out), derived directly from hardware/v2/rtl/neural_processor.v (not assumed) and reusing tools/validation/mac_oracle.py's own pre-existing, hand-verified two's-complement primitives rather than duplicating them. Provides: neuron/layer/network models, a logical memory model of the real V2 SDRAM map (weights/activations/results), deterministic test-vector generators (simple/signed/extremes/zero/random/D-Stress 256x128) with JSON golden-vector export, an FPGA-vs-Python bit-exact comparison utility, four example networks, a CLI (`python -m tools.neural_sim ...`), and a 96-test pytest suite (all passing) covering signed-arithmetic edge cases (including a direct 32-bit wraparound proof), scalar-vs-vectorized neuron cross-checks, layer/memory/vector/comparison tests. This is a golden functional reference (bit-exact numeric result), explicitly NOT a cycle-accurate FPGA simulator -- see tools/neural_sim/README.md for the full scope statement. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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c4763aab10 |
test: directed SDRAM boundary verification + SPI frequency sweep
PRE-PCB CLOSURE Point 1: adds tb_sdram_boundary.v, a directed (not randomized) regression covering address 0/1/last/last-1, an explicit row-boundary crossing, all 3 inter-bank boundary crossings, the real V2 memory-map region boundaries (weights/activations/results), and every DQM byte-mask combination with explicit read-after-write. 21/21 PASS at both 64MHz and 166MHz, zero bugs found. PRE-PCB CLOSURE Point 2: adds tb_spi_freq_sweep.v, a reproducible SPI bit-rate sweep against the real fpga_neural_v2_top (osc_clk driven at the real 64MHz clk_sys rate via the SIM PLL bypass). Found and fixed a race in the new test harness itself (a fixed-time wait before reading a WRITE_MEM/READ_MEM response, too short whenever a periodic AUTO REFRESH delayed the backend) -- not a spi_host_bridge.v defect, confirmed against tb_spi_host_bridge.v's own isolated regression. Determined the real, deterministic CDC margin: the synchronizer requires >=5 system-clock cycles per SPI bit (exactly 64MHz/5 = 12.8MHz); recommends SPI_MAX_VERIFIED=12MHz with real margin below that hard edge. Full writeup: hardware/v2/docs/PRE_PCB_CLOSURE_4POINT.md. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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eb0b0f9170 |
docs: PRE-PCB VERIFICATION FREEZE report + config flash freeze
Adds hardware/v2/docs/PRE_PCB_VERIFICATION.md as the single authoritative pre-schematic verification record: RTL/ERR-0025/ regression re-verification, clock/reset, synthesis/P&R re-audit, setup/hold timing status, the real SDRAM datasheet-parameter audit table (Alliance Memory AS4C4M16SA-6TIN Table 17), SPI host bridge protocol documentation, FPGA power/pinout tables, first-board bring-up and benchmark status, and cross-domain consistency audit. Freezes the FPGA configuration flash: Winbond W25Q32JVSSIQ (32Mbit, SOIC-8, 2.7-3.6V, standard SPI, ECP5 Master-SPI-boot compatible) -- this was the one section-11 item the governing mandate required not be left OPEN. Marks CHIP_READINESS.md/OPEN_ITEMS.md/PINOUT.md/CLOCK_ARCHITECTURE.md/ POWER_ARCHITECTURE.md/SCHEMATIC_READINESS.md as superseded (they predate the SPI host bridge, PLL, and this session's SDRAM datasheet audit) with pointers to the new consolidated document, rather than rewriting each individually. Updates the V2 LaTeX datasheet's status/roadmap chapter to reflect the SDRAM datasheet audit and configuration-flash decisions, rebuilds the PDF (clean compile, 16 pages). Classification: PRE-PCB VERIFIED. Schematic and PCB implementation remain user-owned and not started. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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8890b0abc2 |
fix: ERR-0026 SDRAM tMRD datasheet-unit mismatch at 64MHz
Real Alliance Memory AS4C4M16SA-6TIN datasheet (Rev 5.0, Table 17) specifies tMRD as a fixed 2-tCK cycle count, not an ns value. sdram_controller.v modeled it via ns_to_cycles(12), which rounded to 2 cycles by coincidence at every previously-tested frequency (100/133/166MHz) but rounds to only 1 cycle at the real 64MHz board target -- an under-provisioned one-time init sequence. Fixed by hardcoding T_MRD=2, matching how CAS_LATENCY is already modeled. Verified zero regression: full 9-config legacy sweep + a new dedicated 64MHz config (461/461 PASS each), N=2/N=4 D-Stress (identical cycle counts), board-level smoke test (11/11 PASS). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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d6376e8f2a |
V2 final synthesis/P&R sign-off + LaTeX datasheet port (NOT SILICON READY)
Real synthesis and place-and-route of the actual final board-level
top (fpga_neural_v2_top.v -- SPI bridge, real EHXPLLL, reset_sync,
compute+memory core), against a real, fully ball-assigned LPF. Also
ports the V2 datasheet to LaTeX using V1's own preamble/macros/
typography, and records a real (non-ESP32, honestly labeled) software
reference comparison.
Synthesis (Yosys, real run): 0 CHECK-pass problems, 38 unique warnings
(43 total), all matching this project's own previously-reviewed benign
set (neural_processor.v's known genvar multi-driver artifact, small-
array-to-register unrolling, the real SDRAM DQ tristate bus) -- no new
warnings from the SPI bridge, PLL, or reset synchronizer.
TRELLIS_FF=6322, TRELLIS_COMB=7084, MULT18X18D=32, EHXPLLL=1 (real PLL
confirmed present), DP16KD=0 (all small SRAMs -> distributed RAM).
Place-and-route (nextpnr-ecp5, real runs, 8 seeds, new
v2_board_top.lpf with all 44 top-level signals ball-assigned from the
official Lattice pinout CSV -- no placeholders): 8/8 PASS at 64MHz.
Worst 68.51MHz (seed 4), best 74.17MHz (seed 7), mean 71.16MHz. Zero
unrouted nets, zero placement/routing errors, TRELLIS_IO=44/245 (17%).
Critical path alternates between dependency_manager's own priority
encoder and sdram_unified_backend's own weight-cache hit-index logic,
matching this project's own prior documented timing investigations --
not a new defect.
New: hardware/v2/constraints/v2_board_top.lpf (final LPF, supersedes
v2_unified.lpf for the board-level top), hardware/v2/reports/
step_final_{synthesis,pnr_worst_seed4,timing}.* (raw evidence),
hardware/v2/docs/DatasheetLatex/ (V2 datasheet, real LaTeX build,
16 pages, visually inspected, ported from hardware/v1/docs/
DatasheetLatex/'s own preamble and macros).
Real, honestly-labeled software baseline: the D-Stress arithmetic
(256 neurons x 128 INT8 MACs) compiled and run on THIS development
machine (Apple M4, arm64, NOT an embedded target, NOT ESP32) --
1.28us/inference, included in the datasheet with an explicit
disclosure that no physical ESP32 hardware was available for a real
embedded-target comparison.
Remaining, disclosed, NOT-yet-closed items (this commit does NOT
claim silicon readiness): real KiCad schematic + ERC, PCB layout,
sourced BOM, real power current-budget estimate, SDRAM-datasheet-
parameter cross-check, configuration-flash selection, and (necessarily)
physical fabrication/bring-up. See hardware/v2/docs/DatasheetLatex/
chapters/08-status-roadmap.tex for the complete, itemized checklist.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v
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micheleandClaude Sonnet 5
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68f3c5e403 |
fix(v2): resolve ERR-0025 Part B - SRAM read timing bug in weight/activation memory
Root-causes and fixes the real, disclosed defect left open at the end of the previous STEP20 commit: the board-level SPI host interface produced wrong compute results when jobs were dispatched with realistic (widely time-separated) pacing, even though job registration itself was already confirmed correct at the dependency_manager handshake. Root cause: nms_weight_packed.v and nms_activation_replicated.v both used a REGISTERED SRAM read (rd_data_reg <= mem[addr], one full clock of latency), but nms_memory_manager_stream_wide.v's own read-ahead pipeline (its `rd_pending` bit) is designed around a COMBINATIONAL read -- a request issued this cycle produces data already valid to capture the very next cycle. A busy, multi-tile job (e.g. the STEP19 D-Stress regression, 16 tiles/neuron) never exposes the mismatch, since its own weight/activation prefetch always runs far enough ahead that any given tile has been sitting stable in the SRAM for many cycles by the time it's actually consumed. An uncontested single-tile job has zero such margin: its one tile's read fires on the exact edge the data nominally becomes ready, landing squarely on the missing cycle and permanently latching stale/zero data. Fixed by making both SRAMs' reads combinational, with an explicit same-cycle fill/read address-match bypass for the one hazard a plain combinational read alone would still miss. No FSM, arbiter, or SDRAM controller logic was touched. Verified (Verilator, per this project's own standing DEC-0004 protocol): - tb_fpga_neural_v2_top_smoke.v: 11/11 PASS -- single job, back-to-back jobs, a realistic ~85us-gap job pair, and a parametric sweep of inter-job gaps (100ns/5000ns/50000ns). - STEP19 D-Stress N=2: 49788 cycles, 256/256 bit-exact -- identical cycle count to before this fix (zero regression). - STEP19 D-Stress N=4: 49771 cycles, 256/256 bit-exact -- identical cycle count to before this fix (zero regression). - tb_sdram_unified_backend.v (40/40) and tb_spi_host_bridge.v (18/18) reconfirmed unaffected. The physical SPI host interface is now verified correct end-to-end. Real synthesis/P&R of the board-level top (fpga_neural_v2_top.v) is the deliberate next step, not yet performed this round. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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michele
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18bf038ed5 | v1 datasheet latex source | ||
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micheleandClaude Sonnet 5
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43abf28b5b |
V2.1.0-dev: SPI host bridge + clock/reset architecture (NOT release-ready)
STEP20 work toward the V2 hardware release gate. Adds real new RTL
implementing the three pieces the previous freeze (V2.0.0) explicitly
left open, plus real, disclosed verification findings. Does NOT
declare hardware release complete -- see below.
New RTL:
- spi_host_bridge.v: real SPI slave protocol engine (WRITE_JOB/
WRITE_MEM/READ_MEM/STATUS/RESET opcodes), replacing the 110-pin
reg_* testbench bus as the intended physical host interface.
Isolated regression 18/18 PASS (tb_spi_host_bridge.v); two real
MISO-timing bugs found and fixed during its own development (see
the module's header for the root-cause writeup).
- ecp5_pll_sys_clk.v: real, tool-generated (Project Trellis ecppll)
EHXPLLL wrapper, 16MHz oscillator -> 64MHz system clock, with a
declared (not fabricated) simulation-only PLL bypass.
- reset_sync.v: standard async-assert/sync-deassert reset bridge
gating on external POR and PLL lock.
- fpga_neural_v2_top.v: board-level top wiring the above around the
STEP19 compute+memory design's own already-frozen submodules
(zero modification to neural_processor.v, dependency_manager.v,
sdram_unified_backend.v, or any other previously-frozen file).
Real findings from this step's own re-verification (both logged in
full in hardware/v2/logs/errors.log):
- ERR-0024: the current Icarus Verilog v13.0 install (updated since
the last freeze) gives WRONG bit-exact results for the
already-committed STEP19 regression. Cross-checked against
Verilator per this project's own standing protocol (DEC-0004) --
the STEP19 baseline (single SDRAM, N=2/N=4, raw reg_* interface) IS
bit-exact correct, reconfirmed today, matching the historical cycle
counts exactly. Two provably-zero-behavior-change declaration-order
fixes were required just to get the current toolchain to elaborate
the already-shipped STEP19 files at all.
- ERR-0025: a real SPI-bridge protocol race (fixed) plus a SEPARATE,
real, UNRESOLVED defect -- two jobs dispatched through the real SPI
path with realistic pacing produce wrong compute results, even
though job registration itself is confirmed correct at the
handshake. Root cause not yet isolated. Committed as a known-failing
regression (tb_fpga_neural_v2_top_smoke.v) documenting the gap
honestly rather than hiding it.
Given ERR-0025 Part B is real and unresolved, synthesis/P&R of the new
board-level top was deliberately not attempted this round, and V2
hardware release is NOT declared complete. See decisions.log DEC-0036
and hardware/v2/docs/{CHIP_READINESS,OPEN_ITEMS}.md for the full,
itemized status.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v
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micheleandClaude Sonnet 5
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8e014d8d49 |
V2.0.0 hardware freeze - single SDRAM
FASE #1 hardware freeze for FPGA-Neural V2, N4/P8, single external SDRAM (Alliance Memory AS4C4M16SA-6TIN) serving weights, activations, and results through one physical sdram_controller.v instance. Removes the PSRAM dependency (hardware/v1/rtl/psram_controller.v + memory_interface.v) from the V2 physical path entirely -- V1 itself remains fully unmodified, the golden reference. New RTL: sdram_unified_backend.v (2-way W/AR arbitration over one SDRAM controller, real per-byte DQM write masking added to sdram_controller.v for correct single-byte result writes with no read-modify-write), nms_neural_multiprocessor_sdram_unified.v (the frozen top-level). Two real bugs found and fixed via full-system testing before being accepted (ERR-0023): a deadlock and an off-by-one data-shift bug in the new arbitration logic. Real results: N=4 and N=2 D-Stress bit-exact (256/256 neurons), 40 real AUTO REFRESH events interleaved with zero corruption, real Yosys+nextpnr-ecp5 synthesis/P&R for LFE5U-45F-8CABGA381 (149/245 TRELLIS_IO, a real 45-pin reduction from the prior dual-memory design). Timing is MARGINAL (1/8 P&R seeds >=80MHz), reported honestly rather than masked by the best seed. Real, sourced ball-level pinout for the SDRAM bus + clk/rst (39/149 signals, P&R-verified) using the official Lattice ECP5U-45 pinout CSV found on disk during this step's own pre-commit review -- corrects an earlier draft that wrongly assumed no real pinout data was available. Chip readiness: NO. Real, disclosed blockers remain (no physical host interface exists yet -- the RTL's own reg_* ports are a 110-pin raw test-harness bus; clock source/PLL decision; power/configuration component selection) -- see hardware/v2/docs/{HARDWARE_FREEZE, CHIP_READINESS,OPEN_ITEMS}.md for the complete, itemized status. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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5c9ec618d3 |
docs: publish refreshed V1 datasheet (EN/IT, Rev A1)
Adds the updated professional-template V1 datasheet PDFs to the tracked repo, matching the datasheet's own filename convention. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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63cac6a7e5 |
perf(v2): shared activation cache - further 1.66-2.00x real speedup (DEC-0016)
Implements optimization #2 from the final benchmark campaign's own recommendation, on top of DEC-0015's word-level burst rewrite: a new shared activation_cache.v module fetches a given activation (X) vector from PSRAM once instead of once per neuron sharing it - the exact redundant traffic pattern the dense-layer workloads in this project's benchmark suite exhibit. Each memory_manager's own prefetch_engine now fetches WEIGHTS only; the activation half is requested from the shared cache instead (single-tag, tile-granular, N_SLOTS request ports, its own real word-level PSRAM backend via a new dedicated arbiter port). dataflow_core.v/slot_mem_arbiter.v/neural_multiprocessor.v widened to N_SLOTS+1 ports to arbitrate the cache's traffic alongside each slot's weight traffic. Two real bugs found and fixed during implementation (ERR-0010): a target-bank/pending-bank race in memory_manager.v's activation-cache wiring (the same bug class ERR-0006 already fixed once for pf_target_bank - a later handoff's queued request can overwrite which bank an earlier, still-in-flight request's ack applies to), and a repeat of ERR-0009's N_SLOTS=1 zero-width replication bug in activation_cache.v itself. Real, measured results: the full final-benchmark campaign (24/24 workload/config combinations) re-verified bit-exact. D-Stress cycles fall a further 1.66-2.00x on top of DEC-0015 (~4x combined vs the original byte-level baseline). But the cache's real Fmax cost is much steeper than DEC-0015's own: N_SLOTS=2 (the recommended default, DEC-0014) drops from 133.58 to 87.72 MHz (-34%, margin over 80MHz shrinks from +67% to +9.7%), and N_SLOTS=4 drops to 65.01 MHz - now FAILING the 80MHz target it previously passed. Combined real wall-clock speedup vs the original baseline: N=1 3.86x, N=2 2.45x (both real net wins); N=4 is a real regression once its own now-failing Fmax is honestly used, though N=4 was never the recommended configuration. N_SLOTS=2 remains the recommended default (DEC-0014 unaffected) with a thinner but still real Fmax margin. Cache hit-detection pipelining is flagged as concrete follow-up work if N_SLOTS>2 is ever needed with the cache active - not attempted this round. Logged: simulation/synthesis/timing/benchmark/decisions (DEC-0016)/ experiments (EXP-0016)/errors (ERR-0010)/development.log, ROADMAP.md updated. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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e4a5540b6e |
perf(v2): word-level burst reads - 2.24-2.37x real wall-clock speedup (DEC-0015)
Implements optimization #1 from the final benchmark campaign's own recommendation: exploit psram_controller.v's already-implemented page-mode support (confirmed present by direct inspection) by fetching multiple bytes per real backend transaction instead of one at a time. Root cause addressed: int8_memory_access.v (the byte-level backend prefetch_engine.v originally sat on) already converts every 8-bit logical request into a full 16-bit PSRAM word access internally (mem_addr <= addr >> 1), discarding half of every word it already paid for. prefetch_engine.v/memory_manager.v now speak memory_interface.v's own 16-bit word protocol directly, bypassing int8_memory_access.v entirely - which remains untouched, still frozen V1 (§1/§34); V2 simply reuses the lower layer of the same frozen chain instead of the byte-splitting layer on top of it, the same "reuse what fits" precedent slot_mem_arbiter.v already set. slot_mem_arbiter.v and neural_multiprocessor.v widened to match (lb_n/ub_n added, master port wired directly to memory_interface.v). Real, measured results: M4's own single-job testbench shows 49-56% fewer cycles (166->84, 446->204, 728->322, all still bit-exact). The full final-benchmark campaign (24/24 workload/config combinations) re-verified bit-exact with D-Stress's real wall-clock time (cycles / real POST-P&R Fmax) improving 2.24-2.37x across every N_SLOTS tested, against a small real Fmax cost (unchanged at N=1, -6.2% at N=2, -1.2% at N=4). tb_neural_multiprocessor.v (M8) and tb_benchmark_suite.v (final campaign) needed zero changes - both treat neural_multiprocessor.v as a black box. Only tb_memory_manager.v (M4, rewired to skip int8_memory_access.v) and tb_dataflow_core.v (M7, behavioral model widened to word-level) needed updates. The "real parallel scaling is flat beyond N_SLOTS=2" finding (DEC-0014) still holds - this optimization made the shared PSRAM port more efficient per transaction, not multi-ported - so N_SLOTS=2 remains the recommended default. Logged: simulation/synthesis/timing/benchmark/decisions (DEC-0015)/ experiments (EXP-0015)/development.log. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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3cdaeaee35 |
test(v2): final benchmark campaign - real end-to-end characterization (EXP-0014)
Post-M10, user-requested final benchmark campaign: 6 realistic workloads (16-256 independent neurons in a shared-input dense-layer shape, a random-seeded 2-layer network with real cross-node PSRAM forwarding, and a 6-node 2-hop dependency diamond) x 4 concurrency levels (N_SLOTS=1/2/4/8) through the real, full neural_multiprocessor system (real V1 PSRAM chain, real slot_mem_arbiter). 24/24 runs PASS bit-exact against a software golden model (11,520 individual neuron/ node checks, zero mismatches). Three real bugs found and fixed during the campaign itself (ERR-0009): 1. neural_director.v (M5) had a real RTL bug at N_SLOTS=1 ($clog2(1)=0 makes a replication expression illegal) - never caught because M5-M10 only ever tested N_SLOTS=2/4/8. Fixed with a width-agnostic '0 literal; M5's own testbench re-verified unaffected. 2/3. Two testbench sizing bugs in tb_benchmark_suite.v itself (psram_model DEPTH too small for the Large workload's address range; N_NODES too small for the Stress workload's node-id range, causing a real deadlock via node-id wraparound colliding with an already-DISPATCHED node - a real, honest consequence of DEC-0008's own "no node-slot reclamation" design choice). Headline finding: real parallel scaling is essentially flat beyond N_SLOTS=2 - the single shared PSRAM port saturates at ~91% utilization regardless of slot count, so memory-bound workloads gain only 1.05-1.06x real speedup from N=1 to N=8. Once real POST-P&R Fmax degradation is also factored in, N_SLOTS=4 is measurably 21% SLOWER in real wall-clock time than N_SLOTS=1 for the largest workload tested. N_SLOTS=2 is recommended as the default (DEC-0014, superseding DEC-0012's resource-only "N_SLOTS=8 ceiling" framing for general use). Full 21-section report (every number classified THEORETICAL/ SIMULATED/POST-P&R MEASURED/DERIVED, per the user's own methodology requirements): hardware/v2/docs/benchmarks/ final-benchmark.md Logged: simulation/synthesis/timing/benchmark/decisions (DEC-0014)/ experiments (EXP-0014)/errors (ERR-0009)/development.log, ROADMAP.md updated. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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91bbbe2fe5 |
feat(v2): M10 Optimization - data-driven findings, completes the V2 roadmap
Final milestone of docs/v2-description.md's §33 roadmap, scoped exactly to its own mandate: optimize only on data already gathered in M1-M9, across the pipeline/P_IN/processor-count/scheduling/memory axes - no speculative new features. Three concrete, data-driven results: 1. N_SLOTS=8 (numero processor axis): real synthesis + nextpnr-ecp5 P&R for dataflow_core at N_SLOTS=8, extending M7's N_SLOTS=2/4 sweep to the real DSP ceiling DEC-0005 predicted. 92.63 MHz POST-P&R, PASS at 80MHz, DSP 64/72 (88.9%). DEC-0012 recommends N_SLOTS=8 as the practical ceiling for P_IN=8 on the LFE5U-45F-8BG381. 2. ACC_WIDTH 24 vs 32 (pipeline axis): a real 6-seed nextpnr-ecp5 placement sweep (reusing already-synthesized netlists, no new synthesis needed) resolves EXP-0002's single-seed inconclusiveness. ACC_WIDTH=24 wins on both mean Fmax (+6.2%, 180.71 vs 170.12 MHz) and seed-to-seed variance (~3.4x tighter), on top of its already-known resource advantage. DEC-0013 recommends ACC_WIDTH=24 as the new default. 3. Stall %/utilization (scheduling/memory axes): testbench-only cycle counters added to tb_neural_multiprocessor.v (no RTL touched) close DEC-0011's deferred measurement gap with real data - shared PSRAM port 81.7% utilized, slot 0 95.2%, slot 1 65.2%, no conclusive evidence of harmful fixed-priority starvation at this scale. The 10-milestone V2 roadmap (docs/v2-description.md §33) is now complete end-to-end: real Verilator simulation, real Yosys synthesis, real nextpnr-ecp5 place & route for every milestone, fully logged (EXP-0001..EXP-0013, DEC-0001..DEC-0013, ERR-0001..ERR-0008) with no invented results (§30) and V1 kept frozen and untouched throughout (§1/§34). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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84794a3d25 |
docs(v2): M9 full benchmark - V1 vs V2 comparison table (§32)
Consolidates real, already-measured data from hardware/v1/ (frozen, pre-certified) and V2's own M1-M8 logs into the §32-mandated comparison table, on an apples-to-apples basis: both full systems (V1's spi_neuron_top post_fix_verify vs V2's neural_multiprocessor N_SLOTS=2), both PARALLEL=8/P_IN=8, both using the real unmodified V1 PSRAM backend. Headline, all real measurements: V2 full-system Fmax 142.45 MHz POST-P&R (PASS at 80MHz) vs V1's 68.65 MHz (FAIL at 80MHz); 166 vs 209 real simulated cycles for one neuron's 8-input dot product through the same real PSRAM chain (2.6x wall-clock speedup); peak MAC/cycle 16 (N_SLOTS=2 concurrent slots, real contention already demonstrated in EXP-0009) vs V1's 8 (single sequential core); lower LUT/FF despite V2 already including full dependency-graph scheduling that V1 has none of. 9 of the table's 12 rows carry real sourced numbers; stall %/memory utilization/processor utilization are reported as NOT MEASURED rather than approximated (DEC-0011) - a real number needs dedicated cycle-accounting instrumentation neither system has had built for it yet, and approximating from partial data would violate §30's "no invented results" rule. Deferred to M10, which needs exactly this data to decide what to optimize. No new RTL this milestone - pure data consolidation, logged as EXP-0010. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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6cff2c8a7c |
feat(v2): M8 PSRAM integration - real V1 backend shared across concurrent slots
neural_multiprocessor.v wraps dataflow_core.v (M7, unmodified) around the real, unmodified V1 PSRAM backend chain (int8_memory_access -> memory_interface -> psram_controller), funneling N_SLOTS independent Memory Backend Interface ports through a new generic N-port arbiter (slot_mem_arbiter.v) inspired by (not copied from) V1's own mem_arbiter.v. Real concurrent-slot simulation immediately surfaced a genuine bug (ERR-0008): memory_manager/prefetch_engine's byte-level backend protocol is fire-and-forget (a single-cycle mem_req pulse with no accept handshake) - correct for M4's direct 1:1 connection, but a naive arbiter silently drops a pulse arriving while the shared bus is owned by another slot, hanging that slot forever. Fixed with a per-port pending-request latch, the same "queue, don't drop" idiom already used by memory_manager's own pf_pending register (ERR-0006). Verified (Verilator): 4/4 PASS with 2 slots genuinely contending for one real PSRAM port (444 cycles). No regression on M4's own testbench. Real synthesis + nextpnr-ecp5 P&R (no harness needed - real PSRAM pins keep the top-level at 157 pins): 0 problems, Fmax 142.45 MHz, PASS at 80MHz. Arbitration policy is fixed lowest-index priority, not fairness- balanced (DEC-0010) - consistent with every other "simplest correct policy first" scheduling choice in this roadmap, revisited only if M9's real measurement shows starvation matters. Logged: simulation/synthesis/timing/benchmark/decisions (DEC-0010)/ experiments (EXP-0009)/errors (ERR-0008)/development.log, ROADMAP.md updated. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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77baa8fc16 |
feat(v2): M7 Dataflow Core - full M1-M6 integration, wake-up loop closed end-to-end
dataflow_core.v integrates dependency_manager (M6) -> neural_director (M5) -> N_SLOTS x (memory_manager (M4) + neural_processor (M1)) for the first time. A slot's completion (via neural_director's new slot_node_id tracking, an additive port) feeds back as a producer_done event to dependency_manager, waking up any node that depended on it - closing the dataflow loop without external glue. Verified end-to-end (Verilator) on a 3-node DAG: two independent nodes plus a third depending on both, confirmed to dispatch only after both genuinely complete via real neural_processor computation. 4/4 PASS. Real synthesis + nextpnr-ecp5 P&R via a synthesis-only timing harness (bare per-slot backend ports exceed the LFE5U-45F's TRELLIS_IO budget, same pattern as ERR-0005): N_SLOTS=2 -> 165.15 MHz, N_SLOTS=4 -> 133.19 MHz, both PASS at 80MHz, 0 synthesis problems. Scope explicitly deferred to M8 (DEC-0009): M3's BRAM buffers not wired in yet, per-slot Memory Backend Interface ports not arbitrated to one shared PSRAM master yet - both need real measured data before committing to a design, not guessed at here. Logged: simulation/synthesis/timing/benchmark/decisions (DEC-0009)/ experiments (EXP-0008)/errors (ERR-0007, a Yosys chparam-ordering build quirk, not an RTL bug)/development.log, ROADMAP.md updated. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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8af16d3a12 |
feat(v2): M6 Dependency Manager, multi-dependency wake-up
Implements M6: dependency_manager.v tracks a table of node
descriptors (node_id/state/required_dependencies/resolved_
dependencies/producer_ids -- §10's exact field list), incrementing a
waiting node's resolved count whenever one of its listed producers
completes, transitioning it to READY once resolved==required, and
dispatching ready nodes to the Neural Director (M5) one at a time via
a backpressure-safe valid/ready interface.
Verified with Verilator on a small hand-built DAG: node0/node1 have no
dependencies (dispatch immediately); node2 depends on BOTH node0 AND
node1 ("dipendenze multiple") and stays WAITING until both complete,
confirmed via an explicit negative check after only one resolves;
node3 depends on node0 ALONE, demonstrating a single producer
("node0") satisfying two different consumers' dependencies
("risultati condivisi... piu' consumer") -- node3 fully, node2
partially. 4/4 tests pass.
Scope for this milestone (decisions.log DEC-0008): dependency
COUNTING/readiness only, no direct producer-to-consumer value
forwarding (§11 frames that as a "quando possibile" optimization, not
a correctness requirement -- deferred until real bandwidth
measurements justify it) and no node-slot reclamation after dispatch
(not exercised by any scenario built so far).
Real synthesis: 0 CHECK problems, 763 LUT4/474 FF/0 DSP/0 CCU2C. Real
place&route (module fits the TRELLIS_IO budget as a bare top-level
this time, no harness needed): Fmax 155.30 MHz, PASS at 80MHz.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v
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micheleandClaude Sonnet 5
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2e4cedc761 |
feat(v2): M5 Neural Director, first-free job scheduling
Implements M5: neural_director.v dispatches job descriptors to whichever of N_SLOTS (memory_manager, neural_processor) pairs is currently free (first-free scheduling per §9's initial policy), with a parametric-depth ready-queue FIFO for jobs arriving faster than slots can absorb them. Scope for this milestone (see decisions.log DEC-0007): a reduced 4-state FSM (DIR_IDLE/SCAN_READY/ALLOCATE/ERROR) rather than §9's full 8-state baseline -- dependency tracking, the waiting queue, and wake-up are §10's explicit responsibility (Dependency Manager, M6, not yet built), and slot-completion detection runs as an always-active per-slot tracker rather than a dedicated FSM state, for the same reason DEC-0002 already gave for the Neural Processor's own FSM (gating concurrent per-unit progress behind one shared state kills throughput). Verified with Verilator (N_SLOTS=2, each slot backed by its own independent behavioral memory rather than sharing V1's real PSRAM -- M4 already proved that path for one slot; this milestone's own concern is scheduling across multiple slots): 4/4 tests pass -- 3 jobs submitted to 2 slots (first two dispatch immediately, third correctly queues until a slot frees), and a deliberate burst that forces the ready queue to genuinely fill and recover. Real synthesis: 0 CHECK problems, 382 LUT4/366 FF/4 CCU2C/0 DSP. Real place&route (via a synthesis-only timing harness, same TRELLIS_IO pin-budget reason as M2/M4): Fmax 250.50 MHz, PASS at 80MHz. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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175f697ae1 |
feat(v2): M4 Memory Manager + Prefetch Engine, real V1 PSRAM backend
Implements M4: memory_manager.v (arbitration/buffering/forwarding/ latency hiding/double buffering, §12) + prefetch_engine.v (double-buffered tile fetch, §13), sitting on the REAL, UNMODIFIED V1 PSRAM backend chain (int8_memory_access.v -> memory_interface.v -> psram_controller.v, per §15's explicit mandate not to touch the controller). Verified fully end-to-end with Verilator: real neural_processor (M1) fed entirely by memory_manager, computing against PSRAM-resident X/W tiles (double-buffered prefetch across up to 5 tiles) and writing its result back to PSRAM -- checked via an independent PSRAM read-back, with poison bytes around the operand regions to catch addressing errors. 3/3 jobs pass (1/3/5-tile configurations). Three real RTL bugs found and fixed during integration (full diagnostic trail in errors.log ERR-0006): prefetch_engine had no single-in-flight-request discipline, letting a queued request corrupt the bank bookkeeping of a fetch already running; the fix's own !pf_busy guard had a one-cycle blind spot (pf_busy lags pf_start by a clock) that needed an explicit !pf_start term; and a state-based mux for the shared backend port was off by one cycle, silently dropping the PSRAM result write entirely. Real synthesis: 0 CHECK problems, 851 LUT4/789 FF/108 CCU2C/0 DSP (expected, no multiplication in this module). Real place&route (via a synthesis-only timing harness, needed for the same TRELLIS_IO pin- budget reason as M2's array): Fmax 165.86 MHz, PASS at 80MHz. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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5f0d7f101c |
feat(v2): M3 activation/weight/result buffers, real BRAM mapping
Implements M3: three parametric dual-port buffers for the §12 data-plane (Input/Weight/Result), reusing the proven BRAM-inference idiom from the frozen hardware/v1/rtl/act_buffer.v (synchronous write, synchronous REGISTERED read, no reset on the read register -- keeps Yosys off the LUT-RAM path). Verified with Verilator: 10/10 tests pass (write-then-read correctness, extreme INT8 round-tripping, weight_buffer's full 64-bit tile width round-tripping, undisturbed re-reads). Real synthesis at two depths per module (6 configs total): 0 CHECK problems, every configuration correctly infers DP16KD (never LUT-RAM). Non-obvious real finding: weight_buffer's BRAM cost is driven by its P_IN*DATA_WIDTH tile width, not its DEPTH -- an 8x depth reduction (512->64) left DP16KD usage unchanged at 2, while activation_buffer/result_buffer (byte-wide) scale as naively expected (2->1). All default-depth configs PASS at 80MHz with large margin (287-367 MHz) via real nextpnr-ecp5 place&route. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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3026dcd997 |
feat(v2): M2 Neural Processor Array, N_PROCESSORS resource sweep
Implements M2 of the V2 roadmap: neural_processor_array.v instantiates
N_PROCESSORS independent neural_processor (M1) units, each with its
own dedicated point-to-point job/operand/result interface -- no shared
bus or mux at this level (arbitration is explicitly the Neural
Director's job, M5).
Verified with Verilator (tb_neural_processor_array.v, N_PROCESSORS=4):
7/7 tests pass, including a same-cycle 4-way concurrent launch with
different tile counts and a staggered-start test where a
later-launched, shorter job completes before an earlier-launched,
longer one -- confirming genuine independent concurrent execution
(§18/§34: a blocked/busy processor must not block the others).
Real resource/timing sweep for N_PROCESSORS in {1,2,4,8} (Yosys +
nextpnr-ecp5, real place&route): Fmax stays above the 80MHz target
throughout (159.11 -> 134.70 MHz), but MULT18X18D usage scales
linearly and reaches 88% of the LFE5U-45F's 72 DSPs at N=8 while
LUT/FF stay under 6% -- DSP, not LUT/FF/routing, is the first hard
ceiling on N_PROCESSORS at P_IN=8 (decisions.log DEC-0005). Measured
via a dedicated synthesis-only timing harness after the array's wide
per-processor buses were found to exhaust the device's TRELLIS_IO pin
budget as a bare top-level module beyond N=1 (errors.log ERR-0005) --
not a logic limit, an artifact of testing the array in isolation
before the Memory Manager/Director (M4/M5) exist to consume those
ports on-chip.
Full log trail (development/experiments/errors/decisions/simulation/
synthesis/timing/benchmark.log) in hardware/v2/logs/ per the project's
logging mandate.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v
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micheleandClaude Sonnet 5
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dc0b331d3e |
feat(v2): scaffold hardware/v1 frozen baseline + M1 Neural Processor
Begins the V2 Neural Multiprocessor / Dataflow architecture per docs/v2-description.md, per explicit user request to freeze V1 and start V2 development, copying from V1 what's needed. Scaffold: - hardware/v1/: byte-exact, read-only copy of the current V1 codebase (rtl, testbenches, tools, constraints, a representative subset of synthesis results, and reference docs) -- verified identical via diff/cmp against the live top-level tree before being made filesystem-read-only. The live top-level tree is untouched and remains the project's "production" V1 (see hardware/v1/README.md and hardware/v2/logs/decisions.log DEC-0001 for why copy-not-move). - hardware/v2/: mandatory structure (rtl/sim/constraints/synthesis/ reports/scripts/logs/docs) plus the full logging system required by the spec (development/architecture/simulation/synthesis/timing/ benchmark/decisions/experiments/errors.log). M1 -- Neural Processor (hardware/v2/rtl/neural_processor.v): - 8-stage pipelined perceptron unit (P_IN=8): input align, 8 multipliers, 3-level adder tree, accumulator, bias+activation, INT8 saturation. Genuine 1-tile/cycle throughput, not just a wider combinational datapath. - 7-state FSM (NP_IDLE..NP_ERROR per docs/v2-description.md §6, with 4 baseline states merged into NP_WAIT_OPERANDS -- see decisions.log DEC-0002); valid/ready/data/last stream interfaces per §7. - Bit-exact vs the frozen hardware/v1/rtl/neuron_parallel.v + mac8.v + mac_unit.v: 7/7 tests pass (hardware/v2/sim/tb_neural_processor.v), covering regular/mixed-sign/extreme-INT8 vectors, both activations, a zero-idle-gap back-to-back-tiles throughput check, and an 8-tile job -- verified with Verilator (see below for why). - Real synthesis + place&route (Yosys + nextpnr-ecp5): 0 CHECK problems, Fmax 183.12 MHz at ACC_WIDTH=32 (PASS at 80MHz, ~3x V1's isolated PARALLEL=8 Fmax of 61.71 MHz) and 176.21 MHz at ACC_WIDTH=24 (a user-requested comparison experiment, also bit-exact-verified; see experiments.log EXP-0001/EXP-0002 and benchmark.log). Three real bugs found and resolved during M1 development (full diagnostic record in errors.log): - Two independent, reproducible Icarus Verilog v13.0 scheduling defects (ERR-0001, ERR-0002) that silently produced wrong simulation results for standard sequential Verilog -- confirmed via Verilator 5.050 giving correct results on the same minimal repros. Verilator is now the trusted simulator for hardware/v2/ (decisions.log DEC-0004); Icarus's affected protocol-violation check was removed from the RTL and deferred architecturally to the Neural Director (DEC-0003) rather than chased further. - One real RTL bug (ERR-0003): last0 wasn't gated like valid0, letting a "last tile" tag leak into the pipeline ahead of its actual valid tile on back-to-back jobs. Fixed and verified. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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07a48e401f |
fix: close 7 zero-value/mid-run guard gaps found in re-certification campaign
Fixes all 7 bugs found in the FPGA-Neural re-certification campaign (docs/validation/bugs.md, CERTIFICATION.md), per campaign policy that fixes land as a commit separate from the analysis work (commits 313a199..77e74db): - BUG-005 (CRITICAL): layer_sequencer.v -- RUN_NETWORK(num_layers=0) ran through 256 fabricated layers reading arbitrary PSRAM data as descriptors. Now an immediate no-op. - BUG-007 (CRITICAL): spi_engine.v -- SET_NET_TYPE received mid-run remapped the arbiter mux and hung the in-progress engine. Now rejected while graph_busy/seq_busy, verified not to partially apply. - BUG-002 (MEDIA): neuron_parallel.v -- N_INPUTS=0 bypassed the elaboration-time guard, leaving x_bus/w_bus undriven. Guard extended to reject N_INPUTS==0. - BUG-003 (MEDIA): neuron_parallel.v -- n_inputs_real=0 at runtime had inconsistent behavior across repeated runs. Now an explicit early-out via the existing "finishing" completion path. - BUG-004 (BASSA): neuron_memory.v -- n_neurons_real=0 silently ignored the limit. Fixed at all three entry points into the vulnerable termination checks (STATE_READ_X, STATE_READ_W, and the X->W dispatch). - BUG-006 (BASSA): graph_engine.v -- num_neurons_graph=0 relied on an incidental guard rather than a real one. Now an explicit no-op. - BUG-001 (INFO): removed sim/top.v, confirmed dead code from the pre-INT8 Q8.8 era. Every bug-reproduction testbench is rewritten from observe-only to hard-assert the fixed behavior (sim/*_bug00[2-7]*_tb.v), verified individually and via a full regression (44 testbenches, 43 PASS, 0 FAIL/ERROR, 1 benchmark by design). Re-verified on the real toolchain (Yosys synth_ecp5 + nextpnr-ecp5): 0 constraint errors, Fmax 68.65 MHz (was 67.91 MHz, within known placement noise), critical path structurally unchanged (neuron_parallel/mac8 accumulator carry chain). Updates docs/validation/bugs.md and CERTIFICATION.md to reflect the resolved state, and docs/FPGA-NeuralNetwork-Engine.md + the LaTeX datasheet (IT/EN) with inline notes on each fixed edge case, closing the datasheet/RTL gap flagged in C.13 of the original certification. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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77e74db637 |
docs: final certification verdict for the re-certification campaign
Consolidates Fase 0 + C.1-C.14 + D into one verdict: the project is NOT certifiable without reservations as a whole. Core arithmetic datapath is solid (exhaustively certified where possible); control/ sequencing/arbitration is correct on the happy path (40 real tests pass via an independent regression harness). 7 real bugs found, all traceable to one systemic pattern (unguarded "real=0" boundary values plus one unguarded mid-run configuration write). 2 of 7 are CRITICAL (BUG-005, BUG-007), reachable via documented SPI opcodes under plausible conditions, with real PSRAM corruption or inference-hang risk. None were documented before this campaign. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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8d20a7bfbf |
docs: certify C.9-C.14 + cross-cutting analyses D
C.9 (pinout): certified citing this session's own F1-F7 work; also regenerated a real bitstream for the CURRENT full-system build (ecppack, 0 errors, real part header) rather than relying on an older pre-flash build's bitstream. C.10 (timing): certified citing Fmax re-measured at every structural change this session (54.58->75.30->73.88->66.68->67.91MHz), critical path re-verified identical at every re-synthesis. C.11 (toolchain): full RTL->Yosys->nextpnr-ecp5->ecppack flow re-run on the current build, 0 errors at every stage. Real-silicon behavior explicitly declared NOT certifiable (no physical hardware available). C.12 (netasm): certified citing 20/20 tests plus a real hardware round-trip already demonstrated earlier this session. C.13 (datasheet/RTL coherence): real, current discrepancy found and declared -- none of this campaign's 7 bugs (BUG-001-007) are yet mentioned in the datasheet or engine spec doc. Correct and expected (found after those docs were last updated), flagged as required follow-up after the campaign completes. C.14: page-mode PSRAM and the flash subsystem are actually COMPLETE, not "in progress" as the certification prompt assumed -- verified against real repo state. D (cross-cutting): CDC certified via C.7. Reset scheme found by exhaustive grep across all 20 RTL files to be synchronous-only everywhere (no posedge rst anywhere) -- a real fact, differs from the prompt's async-assert/sync-deassert phrasing, not a defect. FSM: the campaign's own BUG-002-007 ARE FSM defects, found and documented, but no exhaustive reachability analysis of every FSM was done (stated reserve). Width/overflow: 2 real cases found across the whole session. Lint: full-system Yosys check, one real warning (known PSRAM tristate), zero accidental latches confirmed signal-by-signal (25 explicit confirmations). Determinism: no real non-determinism found (the one apparent inconsistency, BUG-003, traced to genuinely different test stimuli between attempts, not unstable behavior for identical stimuli). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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f0a66363de |
test: certify spi_neuron_top mux/pins (C.8), find critical BUG-007
Legitimate dispatch mux and data_ready_n/irq_n pins certified via existing pre-session tests. BUG-007 (CRITICAL), confirmed end-to-end over real simulated SPI: SET_NET_TYPE has no check against graph_busy/seq_busy in rtl/spi_engine.v, and rtl/spi_neuron_top.v's arbiter Port C mux selects between graph_engine/layer_sequencer purely combinationally on the current net_type value -- not latched to whichever engine actually started the in-flight run. Started a valid graph RUN_NETWORK, sent SET_NET_TYPE(dense) immediately after (before completion): STATUS.busy gets stuck (30+ consecutive polls with no done/err, vs. ~12-25us normal completion) -- the graph engine is left waiting for a ram_ready that never arrives via the now-disconnected mux path. Also verified recovery: RESET during the hang brings the system back to a fully working state (a subsequent legitimate dense op completes normally) -- not a permanent lockup, but plain STATUS polling alone would never unstick without a host-side RESET fallback. Full regression: 40/40 real tests pass, 1 new observational test deterministically reproduces BUG-007 and verifies RESET recovery. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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95849c9002 |
docs: certify SPI slave/engine (C.7), confirm len=0 is properly guarded
Certified via existing extensive pre-session coverage (10 tests in spi_engine_tb.v, CDC ratio-variation test in spi_slave_tb.v, explicit unknown-opcode-as-NOP handling), re-confirmed passing in Phase 0. Targeted check given this campaign's recurring pattern (missing zero-value guards, BUG-002 through 006): WRITE_RAM/READ_RAM len=0 IS explicitly guarded (rtl/spi_engine.v:817, transitions to ST_IGNORE) -- confirms the project does not systematically lack these guards, the gap is specific to the modules already flagged. No new bugs found in this aspect. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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6db44efcfd |
test: certify graph_engine gather/guard (C.6), find related BUG-006
Gather/padding/src_id<out_id guard certified via existing solid pre-session tests (graph_engine_tb.v checks act_buffer contents via hierarchical reference, not just final output; graph_engine_guard_tb.v covers 4 adversarial cases incl. recovery). BUG-006 (LOW severity): num_neurons_graph=0 shares BUG-005's exact root cause (neuron_idx is a full 16-bit register, no guard), but graph_engine's existing per-edge src_id<out_id guard incidentally catches most garbage-data patterns fast (err at cycle 58 for a non-trivial test pattern, vs. layer_sequencer's 21761-cycle full run in BUG-005) -- not a designed protection for this case, so not closed as a non-issue, but lower severity given the observed practical risk. Not run to full 65536-iteration completion (impractical for this campaign's time budget) -- limitation stated explicitly. Full regression: 40/40 real tests pass, 1 new observational test. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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f81d7fa1b3 |
test: certify layer_sequencer chain (C.5), find critical BUG-005
Layer chain / ping-pong / busy-done certified via the existing pre-session test, which already verifies the actual ping-pong buffer address used (not just the value) and correct busy/done timing. New finding, BUG-005 (CRITICAL): run_num_layers=0 has no guard at compile time or runtime, and unlike BUG-002's 1-bit group_index (which can never represent the wraparound value), layer_idx here is a full 8-bit register that naturally reaches it. Confirmed empirically with a minimal neuron_memory stub: RUN_NETWORK(0) runs through all 256 possible layer indices (21761 cycles), reading arbitrary PSRAM bytes far past the real descriptor table as if they were valid layer descriptors, running real neuron_memory passes on them, and writing results to ping-pong buffer addresses derived from that arbitrary data. More severe than BUG-002/003/004: reachable via a single documented SPI opcode (RUN_NETWORK), real PSRAM corruption risk rather than just a hang or wrong result. Root cause fully isolated, not just the symptom. Full regression: 40/40 real tests pass, 1 new observational test (no pass/fail by design) deterministically reproduces BUG-005. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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b528901510 |
test: certify mem_arbiter priority order (C.4)
Priority B>C>A>D confirmed correct with distinguishable per-port data (not just "someone got served" but "the right requester got its own data back") across 4 contention scenarios. D-alone case confirms low priority does not mean never granted. Found and fixed a real race in the test harness itself: blocking assignments withdrew loser requests in the same clock edge meant to grant the winner, racing the DUT's own synchronous block -- dut.owner never left SEL_NONE, every wait() blocked forever. Fixed by switching request-signal drives to non-blocking assignments throughout. Documented (not filed as a bug) that D can starve indefinitely under sustained continuous B contention -- standard behavior for a fixed-priority arbiter with no aging, and explicitly outside the header's own stated operating assumption (B/C temporally disjoint in normal operation). Flagged the header's "never starves or corrupts A/B/C" wording as ambiguous about whether it promises D's own progress. Full regression: 40/40 real tests pass. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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3dd75e9e0d |
test: certify memory subsystem addressing (C.3)
int8_memory_access.v byte<->word conversion and byte-lane selection: exhaustive 2048-address test + 6 real read/write round-trips through the FSM handshake. 2054/2054 checks, 0 mismatches, after fixing two bugs in the test harness itself (a same-timestep race reading a non-blocking update one iteration late, and a behavioral memory stub that ignored byte-lane enables on write) -- both documented as test-side, not RTL, issues. memory_interface.v and psram_controller.v not re-verified from scratch: cited against coverage already established/re-confirmed earlier in this same session (page-mode/tCEM against the ISSI datasheet, a real pre-existing power-up request-loss bug found and fixed), re-run clean via the Phase 0 regression harness rather than trusted from WORKLOG text alone. Full regression: 39/39 real tests pass. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
|
14c8d87194 |
test: certify runtime width early-termination (C.2), document BUG-003/004
n_inputs_real/n_neurons_real early termination for valid values is certified real: a "poison" region (data that would saturate the result if read past the claimed limit) confirms no over-read, cycle counts scale proportionally. n_inputs_real non-multiple-of-PARALLEL at runtime matches the documented silent-truncation risk exactly. n_inputs_real=0 / n_neurons_real=0 (BUG-003/004): confirmed incorrect behavior in every repetition, but the exact triggering mechanism was NOT fully isolated -- nearly-identical repeated tests produced different symptoms (clean hang vs. silently processing the full build width vs. a third cycle count matching neither). Reported in full, including the inconsistency itself, rather than picking the cleanest result. The two new permanent testbenches reflect this honestly: the solid early-termination checks are hard assertions, the n_*_real=0 probe is deliberately observe-only given the non-deterministic result. Full regression: 38/38 real tests pass. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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20b0b1f4c0 |
test: certify mac_unit/mac8 datapath (C.1), confirm real N_INPUTS=0 guard gap
mac_unit.v: exhaustive unit test (all 65536 (x,w) combinations at DATA_WIDTH=8, plus 486 boundary acc_in vectors) against an independent Python oracle (tools/validation/mac_oracle.py). 66022/66022 match, 0 reserves. mac8.v: first-ever dedicated unit test (previously only indirect coverage at whatever single PARALLEL neuron_parallel_tb.v happens to use). Verified at PARALLEL=2/8/32 with structural adversarial vectors (catches swapped/duplicated tree wiring), 300 random INT8 pairs per PARALLEL with realistic accumulating acc_in, and worst-case magnitude adversarial vectors. 939/939 match. Confirms BUG-002 (N_INPUTS=0 bypasses the N_INPUTS%PARALLEL elaboration guard) is real, on both simulation and real Yosys synthesis -- root cause: [DATA_WIDTH*N_INPUTS-1:0] becomes [-1:0] for N_INPUTS=0, which both tools treat as a genuine 2-bit undriven vector rather than collapsing to zero width. Includes a documented self-correction: the first verification attempt produced a false "hang" using an invalid one-shot late check of a single-cycle done pulse -- caught by reproducing the same false result on a known-good sanity config before trusting it. Full regression re-run clean after adding 3 new testbenches: 36/36 real tests pass. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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313a1994a4 |
docs: certification campaign Phase 0 -- real inventory, new regression harness
Builds tools/run_regression.py (no reproducible regression script existed before -- every prior "N testbenches, all pass" claim was assembled by hand). Resolves each testbench's dependencies by static analysis of instantiation sites, not from memory, then compiles+runs everything fresh. Independently re-verifies the 33-testbench regression clean (0 real failures) after fixing two false negatives in the harness itself (two tests are deliberate compile-time-failure negative tests, one file is a benchmark with no pass/fail verdict by design -- confirmed by reading each file's own header, not assumed). Findings recorded in docs/validation/: sim/top.v is dead code (references a removed FRAC_BITS parameter from the pre-INT8 Q8.8 era); mac_unit.v/ mac8.v have no dedicated unit testbench, only indirect coverage; the N_INPUTS%PARALLEL elaboration guard does not mathematically cover N_INPUTS=0 (open finding, not yet confirmed reachable -- BUG-002). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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b029e3d95a |
fix: make flash SPI bus electrically independent, drop USRMCLK/CCLK reuse (Phase F7)
The flash subsystem's SCLK previously reused the boot config-SPI's CCLK pad via the ECP5 USRMCLK primitive to save one pin. This made the "exclusive flash bus" claim misleading (SCLK still depended on the config engine's own pad electrically) and carried an unresolved verification gap (USRMCLKTS pad-enable timing never checked against the primary Lattice sysCONFIG Usage Guide). flash_sclk is now a genuine 4th ordinary GPIO pin (E3, bank 7), added purely additively to the real .lpf (git diff: one new line, no existing ball moved). The flash bus is now 4 fully independent wires (sclk/mosi/miso/cs_n), zero pins shared with any ECP5 config primitive -- confirmed by the full-system synthesis reporting USRMCLK 0/1 (0%) utilisation. All 33 project testbenches re-run clean after the port rename (no functional change, only sclk_sim -> sclk). Full-system real synthesis re-verified: 0 constraint errors, Fmax 67.91MHz (up slightly from 66.68MHz, same critical path, not a regression). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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97a21be240 |
feat: flash boot/persistence subsystem (SPI master, copy engine, CRC32 slot catalog)
Adds FPGA-exclusive access to the onboard W25Q128JV SPI NOR flash for weights/bias/network persistence, layered as spi_flash_master (raw SPI, USRMCLK-driven) -> flash_copy_engine (flash<->PSRAM streaming, erase- before-write, Page Program loop) -> flash_slot_manager (16-slot catalog with CRC32), exposed via 8 new SPI opcodes (0x40-0x47). Fixes two pre-existing bugs found during bring-up: a psram_controller.v request lost during power-up, and a one-cycle-pulse race in the PSRAM arbiter request handshake. Full simulation + real Yosys/nextpnr-ecp5 synthesis verification (0 errors, Fmax 66.68MHz) in WORKLOG.md and docs/FPGA-Neural-Flash-Subsystem-Verification.md. Also updates docs/pinout to reflect the 56-signal real .lpf (3 new flash pins) and documents the WRITE_RAM/READ_RAM host backpressure risk found while testing this subsystem. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
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micheleandClaude Sonnet 5
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55c827bedf |
feat: PSRAM page-mode reads + graph engine (Type #2) + real pinout/IRQ pins
PSRAM page-mode read burst support in psram_controller.v: enables the ISSI IS66WVE4M16EBLL-70BLI's page mode via its configuration-register software-access sequence at boot (disabled by default on the real chip), then keeps CE#/OE# asserted after a read so a same-page continuation only pays tAPA (20ns) instead of a full tAA (70ns) random access, with automatic tCEM-safe session closing. Only a WRITE closes the page -- byte-enable changes do not, since int8_memory_access.v alternates them on nearly every access and an early implementation attempt that treated them as a close condition measured a real regression (53.25->61.25 cycles/edge) before being corrected (53.25->37.53 cycles/edge, +42% gather bandwidth). sim/psram_model.v gained independent tAPA/tAA and tCEM enforcement (with a real Verilog same-timestep event-ordering race found and fixed via a #0 sync) so the regression proves real timing compliance, not just data correctness. New sim/psram_page_mode_tb.v; full 26-file regression suite re-run clean. Real nextpnr-ecp5 Fmax re-measured on the full spi_neuron_top system: 75.73MHz (P2, up from 55.59MHz) and 65.13MHz (P8) -- still under the 80MHz target but not regressed, with the critical path confirmed (not assumed) to remain entirely inside neuron_parallel's accumulate chain, never psram_controller. Also includes this session's other already-validated work: the graph engine (Type #2 sparse-graph network: act_buffer, graph_engine, netasm host assembler), real CABGA381 pinout (.lpf, place&route verified) and physical IRQ_N/DATA_READY_N pins, and Phase 7 timing closure logs -- all previously uncommitted, documented in WORKLOG.md. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01LH3jPeJ3eFMfF2v8SQhpkk |
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micheleandClaude Sonnet 5
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7e2711fa27 |
feat: widen ADDR_WIDTH to 23 bits for full 8MB PSRAM addressing
Bumps ADDR_WIDTH's default from 22 to 23 bits across every RTL module (neuron_memory, layer_sequencer, spi_engine, spi_neuron_top, mem_arbiter, int8_memory_access, memory_interface, psram_controller, memory_model) and every testbench that mirrors it, so the system's byte-address space reaches the full 8 MiB the recommended PSRAM part (ISSI IS66WVE4M16EBLL-70BLI, docs/FPGA-Neural-Hardware-Design.md §3) actually provides -- previously only 4 MiB (half the chip) was reachable, since int8_memory_access.v's byte->word address shift (addr >> 1) turned the old 22-bit byte address into only 21 real word bits, one short of the chip's real 22-bit word address (A0-A21). At 23 bits, that same shift lands exactly on all 22 chip address lines, so the whole part is usable now instead of deferred to a future widening. Also fixes a stray 22'd11-sized literal in layer_sequencer.v's descriptor-table address increment (numerically already safe via Verilog's zero-extension, but now correctly unsized so it always matches ADDR_WIDTH instead of silently assuming 22). Updated docs/FPGA-NeuralNetwork-Engine.md's SPI protocol address-field note (23 bits, top 1 reserved bit instead of 2) and docs/FPGA-Neural-Hardware-Design.md's PSRAM section (the "chip has one spare address line" framing is gone now that all 22 are wired and used). Full regression (all 11 ADDR_WIDTH-touching testbenches, plus a Yosys elaboration check of spi_neuron_top with the new default and no override) passes clean. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01WQV3vS9TXaGDJ5cRfnfidt |
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micheleandClaude Sonnet 5
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f6edc01613 |
docs: Phase 7 placement-seed sweep + hardware design document
Phase 7 (docs/FPGA-NeuralNetwork-Engine.md): re-ran nextpnr-ecp5 on the already-synthesized Phase 5 spi_neuron_top netlists (top.json reused, only placement re-seeded) at --seed 1/2/3 for both P8 and P2. Both land in a tight band regardless of seed (P8: 39.5-40.6 MHz, 2.6% spread; P2: 42.5-45.0 MHz, 5.8% spread) -- confirms the Phase 5 timing shortfall is a real structural bottleneck, not placement noise, unlike the much smaller same-tier benchmark design (<2% utilization, huge placer freedom, genuinely noisy). Corrected the earlier "pipeline the saturate stage" candidate fix, which targeted Phase 4's critical path and not the one Phase 5's logic actually shifted to; block RAM for x_mem/w_mem remains the leading candidate, not yet implemented. New docs/FPGA-Neural-Hardware-Design.md: draft hardware design doc for a board carrying the project's actual target device (LFE5U-45F-8BG381C) plus the parallel PSRAM rtl/psram_controller.v is written for. Covers: why not the basic-ecp5-pcb reference board (wrong package/speed grade, no RAM), a real I/O pin budget from Lattice's own CABGA381 pinout table, a researched PSRAM part (ISSI IS66WVE4M16EBLL-70BLI -- 70ns access matches the controller's timing assumption exactly, with a note on the byte/word address shift in int8_memory_access.v so the chip's top address line is correctly left as spare headroom, not a wiring error), clock (16 MHz, no PLL exists yet so CLK_FREQ_MHZ must match whatever oscillator is fitted), power/config reusing the reference board's proven circuitry and errata (config-SPI pin can't double as the application SPI interface), and a BOM/open-items list. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01WQV3vS9TXaGDJ5cRfnfidt |
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micheleandClaude Sonnet 5
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a918c3f1e9 |
feat: configurable activation functions + runtime-configurable network topology
Two related Phase 5 additions, both threaded the same way (a new runtime field defaulting to the pre-existing behavior, settable per-layer via the descriptor table or per-run via SET_BASE): Configurable activation functions: - neuron_parallel.v gains a 2-bit `activation` port (ACT_NONE = linear + two-sided INT8 saturate, ACT_RELU = the original hardwired behavior, kept as the default so every pre-existing caller/testbench is unaffected), threaded through neuron_memory.v. - spi_engine.v: SET_BASE sel=6 (single-layer path); the descriptor table gains a 7th byte (multi-layer path). - Verified in neuron_parallel_tb.v (negative pass-through + negative saturation to -128) and end-to-end in spi_neuron_top_runnetwork_tb.v (a real negative accumulator that ACT_RELU would clamp to 0 comes through unclamped under ACT_NONE, over real SPI/RAM). Runtime network width (one bitstream, any topology up to its build-time max, entirely host-configured over SPI): - neuron_parallel.v gains n_inputs_real, bounding its MAC group loop (n_inputs_real/PARALLEL groups instead of the fixed build-time count). neuron_memory.v gains n_inputs_real/n_neurons_real, bounding its X/W RAM-read loop and its neuron loop. All default to the build-time max, so unconnected callers are unaffected. n_inputs_real must stay a multiple of PARALLEL (same constraint N_INPUTS itself is held to at elaboration time, now the caller's runtime responsibility). - spi_engine.v: SET_BASE sel=7/8 (single-layer path); the descriptor table grows to 11 bytes/layer (+n_inputs_real +n_neurons_real, multi-layer path) -- layer_sequencer.v also now copies only n_neurons_real bytes into the ping-pong buffer, not the full build width. - This is real early termination, not bookkeeping: no RAM zero-padding needed for the unused tail, and it measurably completes faster. neuron_parallel_tb.v TEST 7: 3 cycles vs 6 for a reduced-vs-full run, with garbage loaded into the skipped lanes to prove they're never read. neuron_memory_tb.v TEST 5: through the real PSRAM stack, 209 cycles vs 788. layer_sequencer_tb.v proves a reduced n_neurons_real shortens the ping-pong copy-out itself (bytes beyond the real count stay untouched, not just differing). docs/FPGA-NeuralNetwork-Engine.md: §8.1 opcode/SET_BASE table, new "Runtime network width" subsection, Phase 5 checklist, Current Status table, and the "Core architectural principle" statement updated to reflect that topology (not just trained parameters) is now host-configured at runtime up to a build-time ceiling. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01WQV3vS9TXaGDJ5cRfnfidt |
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michele
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1ddaa9adfd |
feat: real-toolchain Fmax check for Phase 5 spi_neuron_top
Yosys + nextpnr-ecp5 synthesis of the extended spi_neuron_top.v (layer_sequencer + mux + arbiter Port C wired in), speed grade -8, N_INPUTS=32/N_NEURONS=1: PARALLEL=8 -> 40.57 MHz FAIL, PARALLEL=2 -> 42.54 MHz FAIL. Both worse than Phase 4 alone (~52.58/~55.85 MHz for the identical configs) -- the Phase 5 wiring cost real timing headroom. Critical path also shifted from Phase 4's saturation- comparator finding to neuron_memory's x_mem/w_mem LUT-RAM read-mux tree feeding the accumulator. Full analysis and candidate next steps (block RAM for x_mem/w_mem, pipelining, a seed sweep to separate placement noise from a structural bottleneck) recorded under Phase 7 in docs/FPGA-NeuralNetwork-Engine.md. |
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michele
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cfd5e98a0e |
feat: add FPGA-Neural benchmark tooling + same-tier ECP5 P2/P4/P8 results
tools/fpga_benchmark.py: parametric Yosys + nextpnr-ecp5 benchmark harness for the LFE5U-45F-8BG381 (speed grade -8, 80 MHz target), sweeping PARALLEL over the neuron layer and parsing Fmax/LUT4/DFF/DSP utilization out of the nextpnr report into JSON/CSV. synth/ecp5/p2, p4, p8: real synthesis+PnR results backing the same-price-tier FPGA comparison (P2: 87.88 MHz PASS, P4: 75.01 MHz FAIL, P8: 147.62 MHz PASS -- non-monotonic, dominated by placement noise since the whole design uses <2% of the device's LUT4 fabric at every setting, and P8 notably maps to 0 DSP blocks vs 8/16 for P2/P4). synth/ecp5/top.v: benchmark harness top-level, reworked to generate deterministic non-constant X/weights/bias via `keep`-attributed generate blocks so Yosys can't constant-fold the datapath away. Also adds .gitignore for Python's __pycache__/*.pyc. |
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michele
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233d6ff7fb |
feat: complete Phase 5 multi-layer network (RUN_NETWORK) + fix STATUS race
Wires the already-present layer_sequencer.v into the SPI stack: - spi_engine.v: RUN_NETWORK opcode (0x23) + SET_BASE selectors for table_base/buf_a_base/buf_b_base; STATUS.busy/done extended to track the sequencer (seq_busy/seq_done) alongside neuron_memory directly, so done latches on the last layer only. - spi_neuron_top.v: instantiates layer_sequencer, muxes neuron_memory's control inputs between it (while seq_busy) and spi_engine's direct-drive path (legacy single-layer mode), wires the sequencer's own RAM master to mem_arbiter's Port C. Found and fixed a real race while writing the end-to-end test: STATUS's sticky/clear-on-read done bit read its value live/combinationally during transmission and cleared unconditionally on any STATUS read. A done_event landing mid-transmission of a STATUS response byte could be silently dropped -- the host would receive a stale byte while the sticky bit was cleared regardless, hanging any host polling STATUS in a loop. Present since Phase 4, not RUN_NETWORK-specific; only surfaced under this test's continuous polling. Fixed by latching a status_snapshot at opcode-accept time and gating the clear on what was actually transmitted. Tests: spi_engine_tb.v gains RUN_NETWORK/SET_BASE opcode tests (K/L); new layer_sequencer_tb.v unit-tests the sequencer FSM directly (descriptor table, ping-pong buffer addressing, byte-exact copy-out); new spi_neuron_top_runnetwork_tb.v drives a real 2-layer network over simulated SPI end to end (real neuron_memory + PSRAM, hand-computed expected output) and confirms the legacy single-layer path still works afterward. All existing testbenches still pass. |
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micheleandClaude Sonnet 5
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a2bd60e305 |
feat: complete Phase 4 SPI RTL (engine, arbiter, top) + real-RAM e2e test
Implements the rest of the SPI interface (docs §8.1) on top of spi_slave.v from the previous commit: - rtl/spi_engine.v: opcode FSM + register bank, all 8 opcodes (NOP, WRITE_RAM, READ_RAM, RESET, SET_BASE, START, STATUS, READ_OUTPUT, READ_CONFIG). tx_byte is driven combinationally from live state (not reactively on tx_byte_req), applying the prefetch-vs-consume contract documented on spi_slave.v. STATUS.done is a sticky, clear-on-read latch. RAM master port uses the same byte-level convention as neuron_memory.v's external mem_* port. - rtl/mem_arbiter.v: fixed-priority (neuron_memory > spi_engine) grant-and-forward arbiter sharing one byte-level memory port between spi_engine's WRITE_RAM/READ_RAM and neuron_memory's own X/W/bias reads during a run. - rtl/spi_neuron_top.v: full integration -- spi_slave -> spi_engine -> mem_arbiter -> a single shared int8_memory_access -> memory_interface -> psram_controller -> PSRAM pins. neuron_memory's rst is global rst OR'd with the RESET opcode's soft-reset pulse. The host has no direct electrical path to the RAM, only through this chain. Testing: - sim/spi_engine_tb.v: 10 tests (one per opcode + WRITE_RAM/READ_RAM, START idle-vs-busy, STATUS sticky/clear-on-read, extra-MOSI-bytes- ignored, back-to-back transactions) against a synthetic 2-cycle- latency RAM model, isolating the opcode FSM from PSRAM timing. Found and fixed two testbench-only bugs (RTL needed no change): the same delta-zero clock-edge race as spi_slave_tb.v (blocking `nm_done=1` landing on the same sim time as a posedge -- fixed via negedge-based pulsing) and a missing RAM sentinel initialization. - sim/spi_neuron_top_tb.v: end-to-end test against the **real** psram_model.v (not a mock) -- RESET/READ_CONFIG/WRITE_RAM/ READ_RAM/SET_BASE/START/STATUS/READ_OUTPUT all driven purely over simulated SPI. 3/3 scenarios (sum, saturation, ReLU) pass on the first attempt; confirms the arbiter and shared byte<->word bridge are correct against real PSRAM timing, not just a synthetic mock. Real-toolchain verification (Yosys + nextpnr-ecp5 + ecppack): spi_slave.v and spi_engine.v synthesize clean and comfortably clear 80 MHz in isolation (403 MHz / 191 MHz, no DSP usage). The full spi_neuron_top.v integration, however, does NOT meet 80 MHz (~52-56 MHz depending on PARALLEL) -- the critical path is entirely inside neuron_parallel.v's existing saturation comparator (no contribution from the new SPI/arbiter logic), but its routed delay is ~57% worse than in the isolated benchmark due to placement/ routing congestion once SPI + PSRAM logic shares the fabric with it, not resource exhaustion (2% DSP usage). Documented as a Phase 4/7 finding in docs/FPGA-NeuralNetwork-Engine.md -- a floorplanning/ pipelining problem for Phase 7, not a functional-correctness issue (verified independently in simulation against real PSRAM timing). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01WQV3vS9TXaGDJ5cRfnfidt |
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micheleandClaude Sonnet 5
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d716eb04dd |
feat: add spi_slave.v physical layer (Phase 4 SPI RTL, part 1/N)
First real RTL piece of the SPI interface (docs §8.1 protocol draft): the physical layer only -- Mode 0 (CPOL=0, CPHA=0), MSB-first, byte-level shift register with a 3-stage CDC synchronizer for SCLK/MOSI/CS_N (the SPI master clock is asynchronous to the FPGA system clock). Exposes rx_byte/rx_valid, tx_byte/tx_byte_req, and cs_active/cs_start/cs_end to the (not yet written) protocol engine. Documented an important consumer contract on tx_byte_req: it is a prefetch hint (fires once extra after the last byte of every transaction, since the slave cannot know in advance whether the master will keep clocking), not a "byte consumed" event -- a consumer must advance any stateful pointer (e.g. a RAM read address) on rx_valid instead, which fires exactly once per real byte transferred. sim/spi_slave_tb.v: bit-banged SPI master BFM (4 tests: single byte, multi-byte in one CS period, back-to-back transactions, slower SCLK). Two testbench-only bugs found and fixed during bring-up (RTL itself needed no functional change beyond the tx_byte_req contract comment): the BFM was advancing its tx queue on tx_byte_req instead of rx_valid (see contract above), and inter-test reset pulses raced against posedge clk (blocking `rst=1` landing on the same simulation time as a clock edge) -- fixed by asserting/deasserting reset on negedge clk instead. Verified two ways: Icarus Verilog (4/4 tests pass) and the real ECP5 toolchain used for prior benchmarks (Yosys 0.68 synth: 0 problems, 41 FF / 55 LUT4, no latches; nextpnr-ecp5 --45k --package CABGA381 --speed 8 --freq 80: PASS, Fmax 403.23 MHz; ecppack: bitstream generated with no errors). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01WQV3vS9TXaGDJ5cRfnfidt |
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micheleandClaude Sonnet 5
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87efce3d9b |
docs: draft SPI protocol v1 for Phase 4 (opcodes, register map)
Phase 4 (SPI Interface) only had a high-level conceptual sequence (RESET/CONFIGURE/LOAD.../START/WAIT/READ) with no concrete opcodes, framing, or register map -- not enough to start RTL from. Added docs/FPGA-NeuralNetwork-Engine.md §8.1 with a concrete v1 draft: - SPI Mode 0, MSB-first, one opcode byte per CS-low transaction. - Explicit length field on WRITE_RAM/READ_RAM (chosen over CS-edge-delimited streaming: simpler controller, just a byte counter). - READ_CONFIG opcode exposing N_INPUTS/N_NEURONS/PARALLEL/ ADDR_WIDTH/DATA_WIDTH at runtime, so one host firmware build can target different bitstreams. - RESET kept as its own opcode (0x0F), distinct from NOP. - STATUS.done documented as required to be a STICKY, clear-on-read bit in the SPI register bank: neuron_memory.done is a one-cycle pulse that a slow SPI poll would almost certainly miss otherwise. Opcode values themselves are marked explicitly as draft/example, not frozen -- only the framing rules and the two decisions above are meant to stick going into Phase 4 RTL work. No RTL or testbench changes in this commit; design-only. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01WQV3vS9TXaGDJ5cRfnfidt |
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micheleandClaude Sonnet 5
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661363f637 |
feat: extend neuron_memory to support N_NEURONS>1 (Phase 3)
neuron_memory.v only handled a single neuron. Added an N_NEURONS parameter (default 1, fully backward compatible) and a memory-bound neuron loop: X is read once (shared layer input), and for each neuron in turn W and bias are re-read from PSRAM and fed to a single, reused neuron_parallel instance -- no change to the validated compute datapath (neuron_parallel/mac8/mac_unit). Addressing follows layer.v's neuron-major convention: neuron n's weights live at w_base + n*N_INPUTS bytes, its bias at bias_addr + n. Output changed from a single `y` port to a packed `y_bus` (DATA_WIDTH*N_NEURONS bits, neuron-major), matching layer.v's y_bus. - rtl/neuron_memory.v: N_NEURONS parameter, neuron_index/ w_group_base/bias_group_addr tracking, y_reg[] array assembled into y_bus, STATE_WAIT_N now loops back to STATE_READ_W for the next neuron instead of finishing after one. - sim/neuron_memory_tb.v: updated to the new y_bus port (N_NEURONS=1 explicit); all 5 existing tests still pass unchanged, confirming backward compatibility. - sim/neuron_memory_multi_tb.v: new end-to-end test (full memory_interface + psram_controller + psram_model stack) with N_NEURONS=3, validating per-neuron addressing and a single done pulse at the end of the sequence (scale, larger value, ReLU). - Full regression re-run: all existing testbenches still pass. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01WQV3vS9TXaGDJ5cRfnfidt |