n16-timing-closure
35
Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 michele
|
9851930613 | docs: extract V2 datasheet into submodule | ||
 micheleandClaude Sonnet 5
|
8b8ca239ca |
docs: consolidate all V2 datasheets into one current, complete document
The repository had accumulated multiple, contradictory "current state" documents for V2 hardware: an old V1 IT/EN datasheet copy nested inside hardware/v2/docs/datasheet/, a stray untracked duplicate at repo root (docs/DatasheetLatex/), and a second, much older documentation track (hardware/v2/docs/*.md: PRE_PCB_VERIFICATION.md, PRE_PCB_CLOSURE_4POINT.md, MEMORY_UPGRADE_64MB_N8.md, and 10 more) describing an earlier PSRAM/ N_SLOTS<=2 milestone alongside the real, current SDRAM/N_SLOTS=4 board. The LaTeX datasheet's own front matter (features/pinout cover pages) and chapter 9 (benchmarks) were themselves still describing that obsolete architecture, contradicting the real, current chapters 5/7/10 elsewhere in the same document. This commit: - Flattens hardware/v2/docs/datasheet/files/docs/datasheet/v2-en/* up to hardware/v2/docs/datasheet/ (was 4 levels of redundant nesting). - Removes the old V1 IT/EN LaTeX copies and the stray root-level duplicate entirely (recoverable from git history, not from disk). - Preserves the real component reference PDFs (ECP5 eval board, ISSI PSRAM, programming cables) under datasheet/references/. - Removes 13 superseded hardware/v2/docs/*.md status documents after folding every real, unique fact they contained into the datasheet: SPI max verified clock (12MHz, exact 12.8MHz CDC edge), SDRAM directed boundary test (21/21 PASS), 16MHz oscillator MPN (ECS-3225MV-160-BN-TR), and the real FPGA<->SDRAM ball mapping cross-check. - Rewrites the datasheet's own front matter, ch.4 (parameters), ch.8 (top-level module -- was documenting the wrong, non-physical top entirely), and ch.9 (benchmarks) to describe the current, real SDRAM/ N_SLOTS=4 production board, while keeping the real PSRAM-era chapters as clearly-labeled history rather than deleting correctly-measured work. - Fixes a title-page tikzpicture that was clipped off the page edge (pre-existing, unrelated to this change) by scaling it to fit. Net: 85 files changed, -8814/+498 lines. hardware/v2/docs/ now contains exactly one current datasheet plus FIRST_POWER_ON.md (a bring-up runbook, not a duplicate spec). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
1efd63912f |
docs: polish V2 datasheet to professional third-person English
Removed session-log/conversational register leftover from the
interactive drafting process ("the user's own suggestion", "user
confirmed", "user-authored schematic", "user-requested optimizations",
etc.) and replaced with neutral, factual engineering-document
phrasing. No technical content changed -- attribution language only.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v
|
||
|
micheleandClaude Sonnet 5
|
d4792beed7 |
docs: embed real KiCad schematic export in V2 datasheet, verify BOM from source
Exported the schematic (kicad-cli sch export pdf) and BOM (kicad-cli sch export bom) directly from the real KiCad source instead of relying on pasted screenshots/CSVs, then updated ch.10 accordingly: - New "Real KiCad schematic capture" section embeds the two live sheets (FPGA, UnusedBank) as vector figures pulled straight from the project file, plus a note on the three sheet files not reachable from the root hierarchy. - Boot-flash net-name mismatch finding confirmed resolved: FPGA_SPI_* labels now match exactly on both the flash chip and the ECP5's dedicated MSPI pins. - FPGA grade fix (8BG381I -> 8BG381C) now verified directly in the source file's Value field, not just as a stated intent. Real package geometry added: 0.8mm pitch, 20x20 array, 17x17x1.76mm body. - New minor finding: U2's footprint library folder is still named ..._8BG381I even though the Value field is corrected -- not board-affecting (identical physical footprint across grades), but flagged for a future rename. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
7eb02ba4bd |
docs: resolve FPGA grade to commercial (8BG381C), correct temp range data
User confirmed LFE5U-45F-8BG381C (commercial) is the intended part, matching every other reference in this project. Also corrects this chapter's own earlier temperature figures: commercial grade is real TJ 0 to +85C, industrial is TJ -40 to +100C (an earlier draft of this section had the industrial range wrong at -40/+85C). Same "-8" speed grade in both -- the letter suffix only changes the characterized temperature range. KiCad library still needs the part number itself corrected from ...381I to ...381C. Compiled clean (47 pages, 0 errors). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
22e226a087 |
docs: resolve the +1V1 label mystery and close remaining schematic open items
User confirmed TLV62568 (U1) outputs 1.1V, explaining the +1V1 label found near the VCCAUX ferrite (L2) during the schematic review: it belongs to U1's own real output net, merely nearby on the page layout, not routed through the ferrite. VCCAUX remains 2.5V as required by the real Lattice datasheet. All three schematic "open items" from the earlier review are now resolved: TLV62568 EN (R3=499k, confirmed via BOM), the +1V1 label (false alarm, explained above), and the JTAG pull-up array (confirmed 8 discrete 0402 parts via BOM, not a bussed package -- no polarity limitation). Only the boot-flash net-name typo (FGPA/FPGA + SCLK/CLK) remains as a real, open schematic fix, and the FPGA grade discrepancy (8BG381I vs 8BG381C) remains to be confirmed. Compiled clean (47 pages, 0 errors). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
1e36853072 |
docs: clear CAS#/WE# false alarm, resolve TLV73325 EN wiring
User confirmed the real schematic has SDRAM CAS#=F7/WE#=F9 -- matches this chapter exactly. The earlier review's "appear swapped" finding was a misread of the schematic image, not a real error; moved from "real findings" to a cleared checked-item note. TLV73325's EN pin resolved: direct wire to +3.3V (VIN), always-enabled -- no soft-start timing requirement like TLV62568's own R3 pull-up (a plain LDO, no sequencing note in TI's own datasheet), and no dynamic enable/disable control exists elsewhere in this design. Remaining real, open finding: the boot-flash net-name mismatch (FGPA/FPGA typo + SCLK/CLK) still needs a schematic fix. Compiled clean (47 pages, 0 errors). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
e2956d0377 |
docs: add real BOM, flag FPGA grade discrepancy (8BG381I vs 8BG381C)
Real KiCad-exported BOM added to the hardware chapter, cross-checked against every component value this chapter already specifies -- most match exactly (R1/R2 feedback divider, L1/L2, ferrite part number, all three real ICs). One real discrepancy found: U2 is captured as LFE5U-45F-8BG381I (industrial grade) while every other reference in this project uses the C (commercial) grade part -- flagged, not resolved, needs explicit confirmation. Also resolves three earlier open items from the schematic review: R3=499k confirms TLV62568's EN is populated; R5-R12 being 8 discrete 0402 resistors (not a multi-resistor array) confirms the JTAG pull-up/down polarity concern doesn't apply; U5 confirms the previously-missing 16MHz oscillator is now present. Compiled clean (47 pages, 0 errors). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
4cbbe5a29d |
docs: real KiCad schematic review + reserved PCB module section
Adds a dated review section recording today's actual schematic check against every real ball assignment in this chapter: confirmed-correct items, two real findings needing correction (boot-flash net-name mismatch FGPA/FPGA typo + SCLK/CLK label mismatch that would leave the flash electrically disconnected from the ECP5's config engine; SDRAM CAS#/WE# appearing swapped vs. the verified F7/F9 assignment), and open items not resolvable from the schematic image alone (regulator EN pins, a stray +1V1 label near the VCCAUX ferrite, JTAG pull-up/down array polarity). Also reserves a "PCB module form factor" section (castellated-edge SMD module, ~50x25mm) for the future physical layout. Compiled clean (46 pages, 0 errors). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
44be4a7d81 |
docs: reflect flash #1 removal and the N=4 8/8 timing recovery
Datasheet and pinouts.md updated to the current, real state after today's session: flash #1 was implemented then removed (user's own MHz-over-persistence priority call), the clock-closure table now shows the post-revert, post-DEC-0042 numbers (N_SLOTS=4 @ 64MHz 8/8, worst 64.55MHz/best 72.37MHz; N_SLOTS=8 deferred by explicit user request), and the FPGA_DATA_READY any_pending formula is updated to the real counter-based implementation (credited to the user's own diagnosis) that fixed the last failing N=4 seed. Compiled clean (45 pages, 0 errors). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
abaaf21f56 |
docs: datasheet addendum for two-flash programming architecture + FPGA_DATA_READY
Adds a real, dated section to ch.10 (Hardware and board) covering the two-independent-flash architecture (neural-network data vs. boot bitstream), the ESP32<->ECP5 JTAG-only link, and the real CABGA381 ball assignments (JTAG/PROGRAMN/INITN/DONE/CFG[2:0]/MSPI dedicated pins), matching decisions.log DEC-0041. Also closes ch.7's (Host interface) own long-standing "still needed" list: the physical transport (spi_host_bridge.v) and the completion- notification path (FPGA_DATA_READY) it used to flag as missing are both now real -- described with the same system-idle-detector formula implemented in the RTL. Compiled clean (44 pages, 0 errors). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
7d6311bce3 |
feat: two-flash programming architecture, FPGA_DATA_READY, real JTAG/config pinout
Establishes the real ESP32<->ECP5 programming architecture: flash #1 (neural-network data, existing V1 subsystem, ball reserved not yet wired into V2) stays separate from flash #2 (boot bitstream, MSPI auto-boot, CFG[2:0]=[0,1,0]); ESP32 talks JTAG only (bit-banged, no hardware JTAG-master peripheral on S3/C6), updating flash #2 through the ECP5's own internal sysCONFIG-to-SPI bridge, never driving the flash pins directly -- zero bus contention, confirmed against the real Lattice hardware checklist and sysCONFIG user guide. Adds real, verified ball assignments (official Lattice CABGA381 CSV + Project Trellis iodb.json) for JTAG, PROGRAMN/INITN/DONE, CFG[2:0], and the MSPI dedicated pins -- all written to docs/pinouts.md. Implements FPGA_DATA_READY as real RTL: a system-idle detector (dependency_manager's any_pending OR neural_director's !queue_empty OR any active slot), sticky on the busy->idle edge, self-clearing on new work -- not a per-neuron completion pulse, which was confirmed too fine-grained. Bit-exact regression re-verified at N_SLOTS=4 and 8 (zero cycle-count change), new explicit data_ready assertion check added to the D-Stress testbench (PASS both configs), and a fresh Yosys+nextpnr-ecp5 placement check (0 errors, data_ready placed at G3). Also fixes a real, independently-found bug while editing an adjacent file: nms_neural_multiprocessor_sdram_unified.v's own sdram_a port was still [11:0] (12 bits), stale from before the 64MB/13-bit memory upgrade. Not exercised by the real board-level top (which wires SDRAM directly, bypassing this wrapper) but WAS silently truncating A12 in every D-Stress simulation this session, including today's earlier ERR-0029 verification runs. Assessed impact: all D-Stress test addresses used this session decode to rows under 4096 (bit 12 never actually needed), so no false-positive PASS is believed to have resulted -- but the full 64MB space was never actually exercised through this wrapper. Fixed; re-verified bit-exact with identical cycle counts. See decisions.log DEC-0041 for full detail. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
81a9619214 |
chore: remove root-level V1 duplicates, superseded by hardware/v1/ freeze
hardware/v1/ was created (
|
||
|
micheleandClaude Sonnet 5
|
e1cefd13db |
docs: remove hardware/v2/docs/DatasheetLatex, superseded by datasheet/
Replaced by the just-versioned hardware/v2/docs/datasheet/ (the project's real, maintained IT+EN LaTeX datasheet, now including the 2026-09-07 SDRAM upgrade addendum). DatasheetLatex/ was a separate, differently-structured, stale LaTeX document living in the same location -- removed to avoid two competing datasheets under hardware/v2/docs. hardware/v1/docs/DatasheetLatex/ is untouched (V1 scope, not part of this request). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
ff49d3c75d |
docs: bring datasheet/ into the main repo under hardware/v2/docs
Was a separate, untracked directory (DataSheet/) outside the repo. Renamed to lowercase and moved in as hardware/v2/docs/datasheet/, with its own .gitignore for LaTeX build byproducts (compiled PDFs stay tracked, .aux/.log/.toc/etc do not). Now versioned and shares this repo's own remote instead of living untracked on disk. Content: IT+EN LaTeX chapter sources, reference manufacturer PDFs, and compiled datasheet PDFs including the 2026-09-07 SDRAM upgrade addendum (AS4C32M16SB-7BIN part/pinout/timing) in the v2-en chapters. Note: hardware/v2/docs/DatasheetLatex/ (and the v1 sibling) is a separate, already-tracked, differently-structured LaTeX document that predates this move -- left untouched, not merged, since its chapter set and content differ and merging was not requested. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
f14224d0cd |
fix: ERR-0029 sdram_unified_backend weight-cache hit-index critical path
Replace the serial "last-match-wins" priority-scan hit-index encoder with a flat one-hot compare + single-level priority encode, breaking the serially-dependent PFUMX/OFX cascade real P&R showed dominating the N_SLOTS=8 @ 64MHz critical path (55.84MHz worst, 4/8 seeds PASS). Real nextpnr-ecp5 re-verification (32-run matrix, 4 configs x 8 seeds): N_SLOTS=8 @ 64MHz improves to 5/8 PASS (worst 60.12MHz, up from 55.84MHz). N_SLOTS=4 @ 64MHz stays 8/8 PASS but with reduced worst-case margin (WNS +0.605ns, down from +2.143ns) as the critical path relocates to a different, previously-second-worst path in the same module -- a real, disclosed trade-off, not hidden. 80MHz remains NO-GO at both processor counts (re-confirmed on the fixed RTL). Bit-exact, zero functional regression: isolated tb_sdram_unified_backend.v (40/40) and full D-Stress N=4/N=8 (both 256/256 neurons bit-exact vs golden model). See errors.log ERR-0029 and decisions.log DEC-0040 for full root-cause writeup and MEMORY_UPGRADE_64MB_N8.md section 10 for the complete measured data set and AS4C32M16SB-7BIN pinout tables. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013xXuuRUWZScuo1DeYJxs3v |
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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
|
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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
|
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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
|
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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 |
||
|
micheleandClaude Sonnet 5
|
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
|
||
|
micheleandClaude Sonnet 5
|
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 |