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// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed under the Creative Commons Public Domain, for
// any use, without warranty, 2005 by Wilson Snyder.
// SPDX-License-Identifier: CC0-1.0
module t (/*AUTOARG*/
// Inputs
clk
);
input clk;
integer cyc; initial cyc = 0;
reg [63:0] crc;
reg [63:0] sum;
`ifdef ALLOW_UNOPT
/*verilator lint_off UNOPTFLAT*/
`endif
/*AUTOWIRE*/
// Beginning of automatic wires (for undeclared instantiated-module outputs)
wire [31:0] b; // From file of file.v
wire [31:0] c; // From file of file.v
wire [31:0] d; // From file of file.v
// End of automatics
file file (/*AUTOINST*/
// Outputs
.b (b[31:0]),
.c (c[31:0]),
.d (d[31:0]),
// Inputs
.crc (crc[31:0]));
always @ (posedge clk) begin
`ifdef TEST_VERBOSE
$write("[%0t] cyc=%0d crc=%x sum=%x b=%x d=%x\n", $time, cyc, crc, sum, b, d);
`endif
cyc <= cyc + 1;
crc <= {crc[62:0], crc[63] ^ crc[2] ^ crc[0]};
sum <= {b, d}
^ {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("*-* All Finished *-*\n");
$write("[%0t] cyc==%0d crc=%x %x\n", $time, cyc, crc, sum);
if (crc !== 64'hc77bb9b3784ea091) $stop;
if (sum !== 64'h649ee1713d624dd9) $stop;
$finish;
end
end
endmodule
module file (/*AUTOARG*/
// Outputs
b, c, d,
// Inputs
crc
);
input [31:0] crc;
`ifdef ISOLATE
output reg [31:0] b /* verilator isolate_assignments*/;
`else
output reg [31:0] b;
`endif
output reg [31:0] c;
output reg [31:0] d;
always @* begin
// Note that while c and b depend on crc, b doesn't depend on c.
casez (crc[3:0])
4'b??01: begin
b = {crc[15:0],get_31_16(crc)};
d = c;
end
4'b??00: begin
b = {crc[15:0],~crc[31:16]};
d = {crc[15:0],~c[31:16]};
end
default: begin
set_b_d(crc, c);
end
endcase
end
`ifdef ISOLATE
function [31:16] get_31_16 /* verilator isolate_assignments*/;
input [31:0] t_crc /* verilator isolate_assignments*/;
get_31_16 = t_crc[31:16];
endfunction
`else
function [31:16] get_31_16;
input [31:0] t_crc;
get_31_16 = t_crc[31:16];
endfunction
`endif
task set_b_d;
`ifdef ISOLATE
input [31:0] t_crc /* verilator isolate_assignments*/;
input [31:0] t_c /* verilator isolate_assignments*/;
`else
input [31:0] t_crc;
input [31:0] t_c;
`endif
begin
b = {t_crc[31:16],~t_crc[23:8]};
d = {t_crc[31:16], ~t_c[23:8]};
end
endtask
always @* begin
// Any complicated equation we can't optimize
casez (crc[3:0])
4'b00??: begin
c = {b[29:0],2'b11};
end
4'b01??: begin
c = {b[30:1],2'b01};
end
4'b10??: begin
c = {b[31:2],2'b10};
end
4'b11??: begin
c = {b[31:2],2'b00};
end
endcase
end
endmodule
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