Files
FPGA-Neural/hardware/v2/nms/rtl/nms_weight_direct.v
T
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
2026-09-06 13:39:55 +02:00

49 lines
1.9 KiB
Verilog

// ============================================================
// Neural Memory System (NMS) -- Weight SRAM candidate W1 "direct":
// N_SLOTS private, single-port, natively P_IN*DATA_WIDTH-wide memories
// (one per slot). Weights are NEVER shared across neurons (STEP2's own
// analytical conclusion), so there is no arbitration to design at all
// here -- every slot's own fill+read port is fully private. This
// candidate mirrors hardware/v2/rtl/weight_buffer.v's own original
// width/depth structure (EXP-0004/M3) exactly, replicated N_SLOTS
// times, to measure the REAL total DP16KD cost of that replication
// rather than assume it from the single-copy number alone.
// ============================================================
module nms_weight_direct #(
parameter DATA_WIDTH = 8,
parameter P_IN = 8,
parameter N_SLOTS = 4,
parameter MAX_TILES = 16,
parameter TIW = (MAX_TILES <= 1) ? 1 : $clog2(MAX_TILES)
)(
input clk,
input rst,
input [N_SLOTS-1:0] fill_we,
input [N_SLOTS*TIW-1:0] fill_addr_flat,
input [N_SLOTS*DATA_WIDTH*P_IN-1:0] fill_data_flat,
input [N_SLOTS-1:0] rd_en,
input [N_SLOTS*TIW-1:0] rd_addr_flat,
output [N_SLOTS*DATA_WIDTH*P_IN-1:0] rd_data_flat
);
genvar g;
generate
for (g = 0; g < N_SLOTS; g = g + 1) begin : GEN_SLOT
reg [DATA_WIDTH*P_IN-1:0] mem [0:MAX_TILES-1];
reg [DATA_WIDTH*P_IN-1:0] rd_data_reg;
always @(posedge clk) begin
if (fill_we[g])
mem[fill_addr_flat[g*TIW +: TIW]] <= fill_data_flat[g*DATA_WIDTH*P_IN +: DATA_WIDTH*P_IN];
if (rd_en[g])
rd_data_reg <= mem[rd_addr_flat[g*TIW +: TIW]];
end
assign rd_data_flat[g*DATA_WIDTH*P_IN +: DATA_WIDTH*P_IN] = rd_data_reg;
end
endgenerate
endmodule