iverilog/ivtest/ivltests/casesynth3.v

144 lines
3.1 KiB
Verilog

/*
* Copyright (c) 2006 Stephen Williams (steve@icarus.com)
*
* This source code is free software; you can redistribute it
* and/or modify it in source code form under the terms of the GNU
* General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*
* $Id: casesynth3.v,v 1.1 2006/01/21 21:53:09 stevewilliams Exp $"
*/
/*
* This case tests the handling very wide (but sparse) case statements.
*/
module main;
reg clk, rst, set;
reg [3:0] out, load;
reg [10:0] op;
(* ivl_synthesis_on *)
always @(posedge clk or posedge rst)
if (rst) begin
out <= 0;
end else if (set) begin
out <= load;
end else
case (op)
10'b0000000001: /* increment */ out <= out + 1;
10'b1000000000: /* decrement */ out <= out - 1;
10'b1000000001: /* Invert */ out <= ~out;
/* Other ops cause out to not change. */
endcase // case(mod)
(* ivl_synthesis_off *)
initial begin
/* Test rst behavior. */
op = 10'b0000000000;
rst = 1;
set = 0;
load = 0;
clk = 0;
#1 clk = 1;
#1 clk = 0;
if (out !== 4'b0000) begin
$display("FAILED -- out=%b (reset)", out);
$finish;
end
/* Test set behavior */
rst = 0;
set = 1;
load = 4'b0100;
#1 clk = 1;
#1 clk = 0;
if (out !== 4'b0100) begin
$display("FAILED -- out=%b (load)", out);
$finish;
end
/* Test increment behavior */
op = 10'b0000000001;
rst = 0;
set = 0;
load = 0;
#1 clk = 1;
#1 clk = 0;
if (out !== 4'b0101) begin
$display("FAILED -- out=%b (increment 1)", out);
$finish;
end
#1 clk = 1;
#1 clk = 0;
if (out !== 4'b0110) begin
$display("FAILED -- out=%b (increment 2)", out);
$finish;
end
/* Test invert behavior */
op = 10'b1000000001;
#1 clk = 1;
#1 clk = 0;
if (out !== 4'b1001) begin
$display("FAILED == out=%b (invert)", out);
$finish;
end
/* Test NO-OP behavior */
op = 10'b0000000000;
#1 clk = 1;
#1 clk = 0;
if (out !== 4'b1001) begin
$display("FAILED -- out=%b (noop)", out);
$finish;
end
/* Test decrement behavior */
op = 10'b1000000000;
#1 clk = 1;
#1 clk = 0;
if (out !== 4'b1000) begin
$display("FAILED -- out=%b (decrement 1)", out);
$finish;
end
#1 clk = 1;
#1 clk = 0;
if (out !== 4'b0111) begin
$display("FAILED -- out=%b (decrement 2)", out);
$finish;
end
$display("PASSED");
$finish;
end
endmodule // main