Files
FPGA-Neural/sim/layer_tb.v
T
micheleandClaude Sonnet 5 4b5cd4e558 fix: rewrite layer_tb and neuron_parallel_tb for current INT8 architecture
Both testbenches instantiated their DUTs with a FRAC_BITS parameter and
Q8.8 fixed-point 16-bit values, which no longer exist in rtl/neuron_parallel.v
(now plain INT8, DATA_WIDTH=8, hardcoded +127 saturation, ReLU-only clamp).
This made both tests fail elaboration ("parameter FRAC_BITS not found").

Rewrote both benches with integer INT8 stimuli and expectations matching
the current core (no RTL changes): neuron_parallel_tb covers a mixed
vector, ReLU, positive saturation, and mixed values with a boundary
negative bias; layer_tb covers 8 neurons exercising scale, ReLU,
saturation, bias-only, and a sparse weight pattern across groups.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WQV3vS9TXaGDJ5cRfnfidt
2026-09-02 14:16:34 +02:00

236 lines
6.1 KiB
Verilog

`timescale 1ns/1ps
module tb;
parameter DATA_WIDTH = 8;
parameter N_INPUTS = 32;
parameter N_NEURONS = 8;
parameter PARALLEL = 8;
parameter ACC_WIDTH = 32;
reg clk;
reg rst;
reg start;
reg signed [DATA_WIDTH*N_INPUTS-1:0] x_bus;
reg signed [DATA_WIDTH*N_INPUTS*N_NEURONS-1:0]
weights_bus;
reg signed [DATA_WIDTH*N_NEURONS-1:0]
bias_bus;
wire signed [DATA_WIDTH*N_NEURONS-1:0]
y_bus;
wire busy;
wire done;
integer i;
integer errors;
layer #(
.DATA_WIDTH(DATA_WIDTH),
.N_INPUTS(N_INPUTS),
.N_NEURONS(N_NEURONS),
.PARALLEL(PARALLEL),
.ACC_WIDTH(ACC_WIDTH)
) dut (
.clk(clk),
.rst(rst),
.start(start),
.x_bus(x_bus),
.weights_bus(weights_bus),
.bias_bus(bias_bus),
.y_bus(y_bus),
.busy(busy),
.done(done)
);
initial begin
clk = 0;
forever #5 clk = ~clk;
end
task run_layer;
begin
@(posedge clk);
start = 1;
@(posedge clk);
start = 0;
wait(done == 1);
@(posedge clk);
end
endtask
initial begin
$dumpfile("sim/layer.vcd");
$dumpvars(0, tb);
rst = 1;
start = 0;
x_bus = 0;
weights_bus = 0;
bias_bus = 0;
errors = 0;
repeat (2) @(posedge clk);
rst = 0;
/*
* Input vector:
* all inputs = 1
*/
for (i = 0; i < N_INPUTS; i = i + 1)
x_bus[i*DATA_WIDTH +: DATA_WIDTH] = 8'sd1;
/*
* Neuron 0:
* weights = 1
* bias = 0
* result = 32
*/
for (i = 0; i < N_INPUTS; i = i + 1)
weights_bus[
0*N_INPUTS*DATA_WIDTH +
i*DATA_WIDTH +:
DATA_WIDTH
] = 8'sd1;
bias_bus[0*DATA_WIDTH +: DATA_WIDTH] = 8'sd0;
/*
* Neuron 1:
* weights = 3
* result = 96
*/
for (i = 0; i < N_INPUTS; i = i + 1)
weights_bus[
1*N_INPUTS*DATA_WIDTH +
i*DATA_WIDTH +:
DATA_WIDTH
] = 8'sd3;
/*
* Neuron 2:
* weights = -1
* result = -32 -> ReLU = 0
*/
for (i = 0; i < N_INPUTS; i = i + 1)
weights_bus[
2*N_INPUTS*DATA_WIDTH +
i*DATA_WIDTH +:
DATA_WIDTH
] = -8'sd1;
/*
* Neuron 3:
* weights = 8
* result = 256 -> INT8 saturation = 127
*/
for (i = 0; i < N_INPUTS; i = i + 1)
weights_bus[
3*N_INPUTS*DATA_WIDTH +
i*DATA_WIDTH +:
DATA_WIDTH
] = 8'sd8;
/*
* Neuron 4:
* weights = 0
* bias = +5
* result = 5
*/
bias_bus[4*DATA_WIDTH +: DATA_WIDTH] = 8'sd5;
/*
* Neuron 5:
* weights = 0
* bias = -5
* ReLU = 0
*/
bias_bus[5*DATA_WIDTH +: DATA_WIDTH] = -8'sd5;
/*
* Neuron 6:
* weights = 1
* bias = -10
* result = 32 - 10 = 22
*/
for (i = 0; i < N_INPUTS; i = i + 1)
weights_bus[
6*N_INPUTS*DATA_WIDTH +
i*DATA_WIDTH +:
DATA_WIDTH
] = 8'sd1;
bias_bus[6*DATA_WIDTH +: DATA_WIDTH] = -8'sd10;
/*
* Neuron 7:
* first 16 weights = 1, remaining 16 = 0
* bias = +5
* result = 16 + 5 = 21
*
* Exercises a sparse weight pattern across groups
* (PARALLEL = 8 -> GROUPS = 4).
*/
for (i = 0; i < N_INPUTS; i = i + 1)
weights_bus[
7*N_INPUTS*DATA_WIDTH +
i*DATA_WIDTH +:
DATA_WIDTH
] = (i < 16) ? 8'sd1 : 8'sd0;
bias_bus[7*DATA_WIDTH +: DATA_WIDTH] = 8'sd5;
$display("");
$display("==============================");
$display("LAYER TEST (INT8)");
$display("==============================");
run_layer;
$display("Neuron 0 = %5d expected = 32", $signed(y_bus[0*DATA_WIDTH +: DATA_WIDTH]));
$display("Neuron 1 = %5d expected = 96", $signed(y_bus[1*DATA_WIDTH +: DATA_WIDTH]));
$display("Neuron 2 = %5d expected = 0", $signed(y_bus[2*DATA_WIDTH +: DATA_WIDTH]));
$display("Neuron 3 = %5d expected = 127", $signed(y_bus[3*DATA_WIDTH +: DATA_WIDTH]));
$display("Neuron 4 = %5d expected = 5", $signed(y_bus[4*DATA_WIDTH +: DATA_WIDTH]));
$display("Neuron 5 = %5d expected = 0", $signed(y_bus[5*DATA_WIDTH +: DATA_WIDTH]));
$display("Neuron 6 = %5d expected = 22", $signed(y_bus[6*DATA_WIDTH +: DATA_WIDTH]));
$display("Neuron 7 = %5d expected = 21", $signed(y_bus[7*DATA_WIDTH +: DATA_WIDTH]));
if ($signed(y_bus[0*DATA_WIDTH +: DATA_WIDTH]) !== 8'sd32) errors = errors + 1;
if ($signed(y_bus[1*DATA_WIDTH +: DATA_WIDTH]) !== 8'sd96) errors = errors + 1;
if ($signed(y_bus[2*DATA_WIDTH +: DATA_WIDTH]) !== 8'sd0) errors = errors + 1;
if ($signed(y_bus[3*DATA_WIDTH +: DATA_WIDTH]) !== 8'sd127) errors = errors + 1;
if ($signed(y_bus[4*DATA_WIDTH +: DATA_WIDTH]) !== 8'sd5) errors = errors + 1;
if ($signed(y_bus[5*DATA_WIDTH +: DATA_WIDTH]) !== 8'sd0) errors = errors + 1;
if ($signed(y_bus[6*DATA_WIDTH +: DATA_WIDTH]) !== 8'sd22) errors = errors + 1;
if ($signed(y_bus[7*DATA_WIDTH +: DATA_WIDTH]) !== 8'sd21) errors = errors + 1;
$display("busy = %0d", busy);
$display("done = %0d", done);
$display("");
$display("==============================");
if (errors == 0)
$display("PASS - ALL 8 NEURONS");
else
$display("FAIL - %0d ERRORS", errors);
$display("==============================");
$display("LAYER TEST FINISHED");
$display("");
$finish;
end
endmodule