modelsim输出没波形?
本人刚学Verilog,写了个很简单的滤波器,和它的激励,可是用modelsim仿真时,总出不了波形,真不知道为啥,求人指点!我直接粘出来,复制到modelsim里就ok了!
这是滤波器模块:
module fir_lp_8(out,in,clk,rst);
parameter size_in = 8;
parameter size_out = 2*size_in + 1;
parameter h0 = 8'd7;
parameter h1 = 8'd17;
parameter h2 = 8'd32;
parameter h3 = 8'd46;
parameter h4 = 8'd52;
parameter h5 = 8'd46;
parameter h6 = 8'd32;
parameter h7 = 8'd17;
parameter h8 = 8'd7;
input clk,rst;
output [size_out-1 : 0] out;
input [size_in-1 : 0] in;
reg [size_in-1 : 0] samples1;
reg [size_in-1 : 0] samples2;
reg [size_in-1 : 0] samples3;
reg [size_in-1 : 0] samples4;
reg [size_in-1 : 0] samples5;
reg [size_in-1 : 0] samples6;
reg [size_in-1 : 0] samples7;
reg [size_in-1 : 0] samples8;
assign out = in*h0 + samples1*h1 + samples2*h2 + samples3*h3 + samples4*h4
+ samples5*h5 + samples6*h6 + samples7*h7 + samples8*h8;
always @(posedge clk or negedge rst)
if (rst == 0)
begin
samples1 <= 0;
samples2 <= 0;
samples3 <= 0;
samples4 <= 0;
samples5 <= 0;
samples6 <= 0;
samples7 <= 0;
samples8 <= 0;
end
else
begin
samples1 <= in;
samples2 <= samples1;
samples3 <= samples2;
samples4 <= samples3;
samples5 <= samples4;
samples6 <= samples5;
samples7 <= samples6;
samples8 <= samples7;
end
endmodule
这是激励程序:
module stimu_fir_lp_8();
reg clk,rst;
reg [7:0] in;
wire [16:0] out;
initial
begin
clk = 1'b0;
rst = 1'b0;
in = 8'b00001010;
end
always #10 clk = ~clk;
fir_lp_8 test_fir_lp_8(.out(out),.in(in),.clk(clk),.rst(rst));
endmodule
滤波器估计没错,是抄书的,或许激励程序不对,因为是我写的~~~呜呜~~~~