Files
FPGA-Neural/hardware/v1/rtl/layer.v
T
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
2026-09-05 14:06:53 +02:00

81 lines
1.7 KiB
Verilog

module layer #(
parameter DATA_WIDTH = 16,
parameter N_INPUTS = 64,
parameter N_NEURONS = 8,
parameter PARALLEL = 8,
parameter ACC_WIDTH = 40
)(
input clk,
input rst,
input start,
input signed [DATA_WIDTH*N_INPUTS-1:0] x_bus,
input signed [DATA_WIDTH*N_INPUTS*N_NEURONS-1:0]
weights_bus,
input signed [DATA_WIDTH*N_NEURONS-1:0]
bias_bus,
output signed [DATA_WIDTH*N_NEURONS-1:0]
y_bus,
output busy,
output done
);
wire [N_NEURONS-1:0] neuron_busy;
wire [N_NEURONS-1:0] neuron_done;
genvar n;
generate
for (n = 0; n < N_NEURONS; n = n + 1) begin : GEN_NEURON
neuron_parallel #(
.DATA_WIDTH(DATA_WIDTH),
.N_INPUTS(N_INPUTS),
.PARALLEL(PARALLEL),
.ACC_WIDTH(ACC_WIDTH)
) u_neuron (
.clk(clk),
.rst(rst),
.start(start),
.x_bus(x_bus),
.w_bus(
weights_bus[
n*N_INPUTS*DATA_WIDTH
+: N_INPUTS*DATA_WIDTH
]
),
.bias(
bias_bus[
n*DATA_WIDTH
+: DATA_WIDTH
]
),
.y(
y_bus[
n*DATA_WIDTH
+: DATA_WIDTH
]
),
.busy(neuron_busy[n]),
.done(neuron_done[n])
);
end
endgenerate
assign busy = |neuron_busy;
assign done = &neuron_done;
endmodule