verilator/test_regress/t/t_select_negative.v
2022-05-01 10:10:00 -04:00

71 lines
2.0 KiB
Systemverilog

// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed under the Creative Commons Public Domain, for
// any use, without warranty, 2008 by Wilson Snyder.
// SPDX-License-Identifier: CC0-1.0
module t (/*AUTOARG*/
// Inputs
clk
);
input clk;
integer cyc = 0;
reg [63:0] crc;
reg [63:0] sum;
wire [15:-16] sel2 = crc[31:0];
wire [80:-10] sel3 = {crc[26:0],crc};
wire [3:0] out21 = sel2[-3 : -6];
wire [3:0] out22 = sel2[{1'b0,crc[3:0]} - 16 +: 4];
wire [3:0] out23 = sel2[{1'b0,crc[3:0]} - 10 -: 4];
wire [3:0] out31 = sel3[-3 : -6];
wire [3:0] out32 = sel3[crc[5:0] - 6 +: 4];
wire [3:0] out33 = sel3[crc[5:0] - 6 -: 4];
// Aggregate outputs into a single result vector
wire [63:0] result = {40'h0, out21, out22, out23, out31, out32, out33};
reg [15:-16] sel1;
initial begin
// Path clearing
sel1 = 32'h12345678;
if (sel1 != 32'h12345678) $stop;
if (sel1[-13 : -16] != 4'h8) $stop;
if (sel1[3:0] != 4'h4) $stop;
if (sel1[4 +: 4] != 4'h3) $stop;
if (sel1[11 -: 4] != 4'h2) $stop;
end
// Test loop
always @ (posedge clk) begin
`ifdef TEST_VERBOSE
$write("[%0t] sels=%x,%x,%x %x,%x,%x\n", $time, out21,out22,out23, out31,out32,out33);
$write("[%0t] cyc==%0d crc=%x result=%x\n", $time, cyc, crc, result);
`endif
cyc <= cyc + 1;
crc <= {crc[62:0], crc[63] ^ crc[2] ^ crc[0]};
sum <= result ^ {sum[62:0], sum[63] ^ sum[2] ^ sum[0]};
if (cyc==0) begin
// Setup
crc <= 64'h5aef0c8d_d70a4497;
end
else if (cyc<10) begin
sum <= 64'h0;
end
else if (cyc<90) begin
end
else if (cyc==99) begin
$write("[%0t] cyc==%0d crc=%x sum=%x\n", $time, cyc, crc, sum);
if (crc !== 64'hc77bb9b3784ea091) $stop;
`define EXPECTED_SUM 64'hba7fe1e7ac128362
if (sum !== `EXPECTED_SUM) $stop;
$write("*-* All Finished *-*\n");
$finish;
end
end
endmodule