micheleandClaude Sonnet 5
dc0b331d3e
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
179 lines
5.1 KiB
Verilog
179 lines
5.1 KiB
Verilog
module int8_memory_access #(
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parameter ADDR_WIDTH = 23
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)(
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input wire clk,
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input wire rst,
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// ============================================================
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// INT8 interface
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//
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// addr is BYTE address
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// ============================================================
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input wire req,
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input wire wr,
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input wire [ADDR_WIDTH-1:0] addr,
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input wire signed [7:0] wdata,
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output reg signed [7:0] rdata,
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output reg ready,
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// ============================================================
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// 16-bit memory interface
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// ============================================================
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output reg mem_req,
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output reg mem_wr,
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output reg [ADDR_WIDTH-1:0] mem_addr,
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output reg [15:0] mem_wdata,
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output reg mem_lb_n,
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output reg mem_ub_n,
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input wire [15:0] mem_rdata,
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input wire mem_ready
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);
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// ============================================================
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// State machine
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// ============================================================
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localparam STATE_IDLE = 2'd0;
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localparam STATE_WAIT = 2'd1;
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reg [1:0] state;
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// ============================================================
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// Latched byte address
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// ============================================================
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reg [ADDR_WIDTH-1:0] addr_reg;
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// ============================================================
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// Main state machine
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// ============================================================
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always @(posedge clk) begin
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if (rst) begin
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state <= STATE_IDLE;
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addr_reg <= {ADDR_WIDTH{1'b0}};
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rdata <= 8'sd0;
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ready <= 1'b0;
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mem_req <= 1'b0;
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mem_wr <= 1'b0;
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mem_addr <= {ADDR_WIDTH{1'b0}};
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mem_wdata <= 16'h0000;
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// Active-low byte enables:
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// 1 = disabled
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mem_lb_n <= 1'b1;
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mem_ub_n <= 1'b1;
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end else begin
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// ready is a one-cycle pulse
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ready <= 1'b0;
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// mem_req is a one-cycle pulse
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mem_req <= 1'b0;
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case (state)
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// =================================================
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// IDLE
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// =================================================
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STATE_IDLE: begin
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if (req) begin
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addr_reg <= addr;
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mem_req <= 1'b1;
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mem_wr <= wr;
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// ------------------------------------------------
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// Byte address -> 16-bit word address
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//
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// addr[0] = 0 -> low byte
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// addr[0] = 1 -> high byte
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// ------------------------------------------------
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mem_addr <= addr >> 1;
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// ------------------------------------------------
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// Select byte
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// ------------------------------------------------
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if (addr[0] == 1'b0) begin
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// Low byte
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mem_lb_n <= 1'b0;
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mem_ub_n <= 1'b1;
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// Data goes into DQ[7:0]
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mem_wdata <= {8'h00, wdata};
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end else begin
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// High byte
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mem_lb_n <= 1'b1;
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mem_ub_n <= 1'b0;
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// Data goes into DQ[15:8]
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mem_wdata <= {wdata, 8'h00};
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end
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state <= STATE_WAIT;
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end
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end
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// =================================================
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// WAIT
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// =================================================
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STATE_WAIT: begin
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if (mem_ready) begin
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// ------------------------------------------------
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// Extract requested byte
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// ------------------------------------------------
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if (addr_reg[0] == 1'b0)
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rdata <= mem_rdata[7:0];
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else
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rdata <= mem_rdata[15:8];
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ready <= 1'b1;
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state <= STATE_IDLE;
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end
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end
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// =================================================
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// Default
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// =================================================
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default: begin
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state <= STATE_IDLE;
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mem_req <= 1'b0;
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mem_lb_n <= 1'b1;
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mem_ub_n <= 1'b1;
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end
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endcase
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end
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end
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endmodule |