Speech256/verilog/pwmdac/pwmdac_tb.v

65 lines
1.5 KiB
Verilog

// SPEECH 256
// Copyright (C) 2017 Niels Moseley / Moseley Instruments
// http://www.moseleyinstruments.com
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 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, see <http://www.gnu.org/licenses/>.
//
//
// PWMDAC testbench
//
module PWMDAC_TB;
reg clk, rst_an;
reg signed [7:0] din;
wire dacout, din_ack;
real accu;
PWMDAC u_pwmdac (
.clk (clk),
.rst_an (rst_an),
.din (din),
.din_ack (din_ack),
.dacout (dacout)
);
initial
begin
$dumpfile ("pwmdac.vcd");
$dumpvars;
clk = 0;
rst_an = 0;
din = 0;
accu = 0;
#3
rst_an = 1;
#655360
$finish;
end
always @(posedge clk)
begin
if (din_ack)
begin
accu = accu + 1.0/256.0;
if (accu > 1.0)
accu = -1.0;
din = $rtoi($sin(2.0*3.1415927*accu)*127.0);
end
end
always
#5 clk = !clk;
endmodule