tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it.module TopModule (
input wire clk,
input wire rst,
input wire wr_i,
input wire [31:0] wr_data,
input wire wr_last_i,
output wire wr_ready_o,
output reg m_tvalid_o,
output reg [31:0] m_tdata_o,
output reg m_tlast_o,
input wire m_tready_i
);
// Depth-8 FIFO storage
reg [31:0] mem [0:7];
reg lastmem [0:7];
reg [2:0] wptr;
reg [2:0] rptr;
reg [3:0] count;
// Stream engine bookkeeping
reg [31:0] last_payload; // data of the payload that requested pads
reg [1:0] pad_pending; // 0, 1, or 2 pad beats still to emit
reg pend_is_payload; // current loaded beat is a FIFO payload
reg pend_last; // that payload's wr_last flag
wire fifo_empty = (count == 4'd0);
wire fifo_full = (count == 4'd8);
// Ready when not full (and cleared during reset)
assign wr_ready_o = !rst && !fifo_full;
wire xfer = m_tvalid_o && m_tready_i;
wire do_push = wr_i && wr_ready_o;
// A new beat may be loaded only when the stream is currently idle.
// Because xfer requires m_tvalid_o=1, loading can never coincide with an
// xfer edge, guaranteeing at least one idle cycle between accepted beats.
wire load_now = !m_tvalid_o;
wire load_pad = load_now && (pad_pending != 2'd0);
wire load_fifo = load_now && (pad_pending == 2'd0) && !fifo_empty;
wire do_pop = load_fifo;
always @(posedge clk) begin
if (rst) begin
m_tvalid_o <= 1'b0;
m_tdata_o <= 32'd0;
m_tlast_o <= 1'b0;
wptr <= 3'd0;
rptr <= 3'd0;
count <= 4'd0;
last_payload <= 32'd0;
pad_pending <= 2'd0;
pend_is_payload <= 1'b0;
pend_last <= 1'b0;
end else begin
// ---- Write side: push into FIFO ----
if (do_push) begin
mem[wptr] <= wr_data;
lastmem[wptr] <= wr_last_i;
wptr <= wptr + 3'd1;
end
// ---- Stream side ----
if (xfer) begin
// Accepted beat: deassert valid, hold data.
m_tvalid_o <= 1'b0;
// If the accepted beat was a last-flagged payload, schedule pads.
if (pend_is_payload && pend_last) begin
pad_pending <= 2'd2;
last_payload <= m_tdata_o;
end
end else if (load_pad) begin
// Emit a pad beat.
m_tvalid_o <= 1'b1;
m_tdata_o <= last_payload ^ 32'h0BADF00D;
m_tlast_o <= (pad_pending == 2'd1); // last only on 2nd pad
pad_pending <= pad_pending - 2'd1;
pend_is_payload <= 1'b0;
end else if (load_fifo) begin
// Load next payload from FIFO.
m_tvalid_o <= 1'b1;
m_tdata_o <= mem[rptr];
m_tlast_o <= 1'b0; // payloads never last
pend_is_payload <= 1'b1;
pend_last <= lastmem[rptr];
rptr <= rptr + 3'd1;
end
// ---- Occupancy: single update for push and/or pop ----
case ({do_push, do_pop})
2'b10: count <= count + 4'd1;
2'b01: count <= count - 4'd1;
default: count <= count; // 00 (idle) or 11 (both -> net zero)
endcase
end
end
endmodule
Check for available Verilog simulators
which iverilog verilator 2>/dev/null; echo "---"
/usr/bin/iverilog --- [stdout] /usr/bin/iverilog ---
Compile and run a directed testbench
cat > /tmp/tb.sv <<'EOF'
module tb;
reg clk=0, rst=1, wr_i=0, wr_last_i=0, m_tready_i=0;
reg [31:0] wr_data=0;
wire wr_ready_o, m_tvalid_o, m_tlast_o;
wire [31:0] m_tdata_o;
TopModule d(.clk(clk),.rst(rst),.wr_i(wr_i),.wr_data(wr_data),.wr_last_i(wr_last_i),
.wr_ready_o(wr_ready_o),.m_tvalid_o(m_tvalid_o),.m_tdata_o(m_tdata_o),
.m_tlast_o(m_tlast_o),.m_tready_i(m_tready_i));
always #5 clk=~clk;
task push(input [31:0] d, input l);
begin
@(negedge clk); wr_i=1; wr_data=d; wr_last_i=l;
@(posedge clk); #1;
@(negedge clk); wr_i=0;
end
endtask
integer i;
initial begin
@(negedge clk); rst=1; @(negedge clk); rst=0;
// push 3 payloads, last one flagged
push(32'hAAAA0001,0);
push(32'hAAAA0002,0);
push(32'hCAFEBABE,1);
// now stream them out with tready always 1
m_tready_i=1;
for(i=0;i<40;i=i+1) begin
@(posedge clk); #1;
if(m_tvalid_o) $display("t=%0t data=%h last=%b",$time,m_tdata_o,m_tlast_o);
end
$finish;
end
endmodule
EOF
iverilog -g2012 -o /tmp/sim /app/dut.sv /tmp/tb.sv && vvp /tmp/simt=96 data=aaaa0002 last=0 t=116 data=cafebabe last=0 t=136 data=c1534ab3 last=0 t=156 data=c1534ab3 last=1 /tmp/tb.sv:34: $finish called at 476 (1s) [stdout] t=96 data=aaaa0002 last=0 t=116 data=cafebabe last=0 t=136 data=c1534ab3 last=0 t=156 data=c1534ab3 last=1 /tmp/tb.sv:34: $finish called at 476 (1s)
Monitor accepted beats via xfer
cat > /tmp/tb2.sv <<'EOF'
module tb;
reg clk=0, rst=1, wr_i=0, wr_last_i=0, m_tready_i=0;
reg [31:0] wr_data=0;
wire wr_ready_o, m_tvalid_o, m_tlast_o;
wire [31:0] m_tdata_o;
TopModule d(.*);
always #5 clk=~clk;
task push(input [31:0] dd, input l);
begin @(negedge clk); wr_i=1; wr_data=dd; wr_last_i=l;
@(negedge clk); wr_i=0; end
endtask
integer n=0;
// capture accepted beats (xfer)
always @(posedge clk) if(!rst && m_tvalid_o && m_tready_i) begin
$display("XFER data=%h last=%b", m_tdata_o, m_tlast_o); n=n+1; end
initial begin
@(negedge clk); rst=0;
push(32'hAAAA0001,0);
push(32'hCAFEBABE,1);
m_tready_i=1;
repeat(30) @(posedge clk);
// second burst, ready toggling
push(32'h11110000,1);
repeat(20) @(posedge clk);
$finish;
end
endmodule
EOF
iverilog -g2012 -o /tmp/sim2 /app/dut.sv /tmp/tb2.sv && vvp /tmp/sim2XFER data=aaaa0001 last=0 XFER data=cafebabe last=0 XFER data=c1534ab3 last=0 XFER data=c1534ab3 last=1 XFER data=11110000 last=0 XFER data=1abcf00d last=0 XFER data=1abcf00d last=1 /tmp/tb2.sv:25: $finish called at 555 (1s) [stdout] XFER data=aaaa0001 last=0 XFER data=cafebabe last=0 XFER data=c1534ab3 last=0 XFER data=c1534ab3 last=1 XFER data=11110000 last=0 XFER data=1abcf00d last=0 XFER data=1abcf00d last=1 /tmp/tb2.sv:25: $finish called at 555 (1s)
Check backpressure hold and idle spacing
cat > /tmp/tb3.sv <<'EOF'
module tb;
reg clk=0, rst=1, wr_i=0, wr_last_i=0, m_tready_i=0;
reg [31:0] wr_data=0;
wire wr_ready_o, m_tvalid_o, m_tlast_o;
wire [31:0] m_tdata_o;
TopModule d(.*);
always #5 clk=~clk;
task push(input [31:0] dd, input l);
begin @(negedge clk); wr_i=1; wr_data=dd; wr_last_i=l;
@(negedge clk); wr_i=0; end
endtask
integer prev_valid=0;
reg [31:0] hold_data; integer holding=0;
always @(posedge clk) begin
// check: two consecutive cycles cannot both be xfers (idle cycle needed)
// check: while tready=0 and tvalid=1, data holds
end
initial begin
@(negedge clk); rst=0;
push(32'h00000001,0);
push(32'h00000002,0);
// ready with a bubble pattern
$monitor("t=%0t v=%b d=%h l=%b rdy=%b tready=%b",$time,m_tvalid_o,m_tdata_o,m_tlast_o,wr_ready_o,m_tready_i);
// hold tready low a few cycles: data must hold
m_tready_i=0; repeat(4) @(posedge clk);
m_tready_i=1; @(posedge clk);
m_tready_i=0; repeat(3) @(posedge clk);
m_tready_i=1; repeat(6) @(posedge clk);
$finish;
end
endmodule
EOF
iverilog -g2012 -o /tmp/sim3 /app/dut.sv /tmp/tb3.sv && vvp /tmp/sim3t=50 v=1 d=00000001 l=0 rdy=1 tready=0 t=85 v=1 d=00000001 l=0 rdy=1 tready=1 t=95 v=0 d=00000001 l=0 rdy=1 tready=0 t=105 v=1 d=00000002 l=0 rdy=1 tready=0 t=125 v=1 d=00000002 l=0 rdy=1 tready=1 t=135 v=0 d=00000002 l=0 rdy=1 tready=1 /tmp/tb3.sv:29: $finish called at 185 (1s) [stdout] t=50 v=1 d=00000001 l=0 rdy=1 tready=0 t=85 v=1 d=00000001 l=0 rdy=1 tready=1 t=95 v=0 d=00000001 l=0 rdy=1 tready=0 t=105 v=1 d=00000002 l=0 rdy=1 tready=0 t=125 v=1 d=00000002 l=0 rdy=1 tready=1 t=135 v=0 d=00000002 l=0 rdy=1 tready=1 /tmp/tb3.sv:29: $finish called at 185 (1s)
Check FIFO full stall and reset clearing
cat > /tmp/tb4.sv <<'EOF'
module tb;
reg clk=0, rst=1, wr_i=0, wr_last_i=0, m_tready_i=0;
reg [31:0] wr_data=0;
wire wr_ready_o, m_tvalid_o, m_tlast_o; wire [31:0] m_tdata_o;
TopModule d(.*);
always #5 clk=~clk;
integer i, accepted=0;
initial begin
@(negedge clk); rst=0;
// keep tready low so nothing drains; try to push 12 beats
m_tready_i=0; wr_i=1; wr_last_i=0;
for(i=0;i<12;i=i+1) begin
wr_data=i;
@(posedge clk); #1;
if(wr_ready_o===1'b0) $display("full-stall at attempt %0d ready=%b",i,wr_ready_o);
end
wr_i=0;
@(negedge clk);
// assert reset, check outputs cleared
rst=1; @(posedge clk); #1;
$display("after rst: v=%b d=%h l=%b rdy=%b",m_tvalid_o,m_tdata_o,m_tlast_o,wr_ready_o);
$finish;
end
endmodule
EOF
iverilog -g2012 -o /tmp/sim4 /app/dut.sv /tmp/tb4.sv && vvp /tmp/sim4full-stall at attempt 8 ready=0 full-stall at attempt 9 ready=0 full-stall at attempt 10 ready=0 full-stall at attempt 11 ready=0 after rst: v=0 d=00000000 l=0 rdy=0 /tmp/tb4.sv:22: $finish called at 136 (1s) [stdout] full-stall at attempt 8 ready=0 full-stall at attempt 9 ready=0 full-stall at attempt 10 ready=0 full-stall at attempt 11 ready=0 after rst: v=0 d=00000000 l=0 rdy=0 /tmp/tb4.sv:22: $finish called at 136 (1s)
No file changes, the agent left the workspace untouched.
TEST dut_present: PASS (/app/dut.sv exists) TEST dut_forbidden: PASS (no forbidden constructs) TEST dut_standalone: PASS (DUT elaborates standalone) TEST harness_prepare: PASS (harness names nonce-renamed) TEST dut_compiles: PASS (compiled with held-back reference/testbench) TEST simulation_completed: PASS (Mismatches: 0 in 256 samples) TEST reference_equivalence: PASS (all 256 samples matched reference)
Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_eaa79080ebab4ef9. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.
Trial trial_eaa79080ebab4ef9 · verifier authoritative; classifier explanatory.