这是第一次用Verilog写FFT，代码写得很烂，但是基本功能还是能实现的。希望走过路过的大佬能够多多指出不足，提出改进方向，也欢迎同学们向我提出所有让自己感到困惑的内容，大家一起进步。话不多说，祭出代码。整个工程已上传至我的网盘，大家如果需要可以私聊我，开源精神，一切共享。
首先是FFT源码
//******************************************************
//Data: 2019-9-10
//Name: Li Fuong
//Theme: 8_FFT_2
//******************************************************
module FFT_8(
clk,
rst_n,
x_r_0, //输入实部
x_r_1,
x_r_2,
x_r_3,
x_r_4,
x_r_5,
x_r_6,
x_r_7,
x_i_0, //输入虚部
x_i_1,
x_i_2,
x_i_3,
x_i_4,
x_i_5,
x_i_6,
x_i_7,
y_r_0, //输出实部
y_r_1,
y_r_2,
y_r_3,
y_r_4,
y_r_5,
y_r_6,
y_r_7,
y_i_0, //输出虚部
y_i_1,
y_i_2,
y_i_3,
y_i_4,
y_i_5,
y_i_6,
y_i_7
);
input clk;
input rst_n;
//输入占5位，在保持最高位为0的条件下可输入0~15的采样值
input signed [4:0] x_r_0;
input signed [4:0] x_r_1;
input signed [4:0] x_r_2;
input signed [4:0] x_r_3;
input signed [4:0] x_r_4;
input signed [4:0] x_r_5;
input signed [4:0] x_r_6;
input signed [4:0] x_r_7;
input signed [4:0] x_i_0;
input signed [4:0] x_i_1;
input signed [4:0] x_i_2;
input signed [4:0] x_i_3;
input signed [4:0] x_i_4;
input signed [4:0] x_i_5;
input signed [4:0] x_i_6;
input signed [4:0] x_i_7;
//输出占7位
output reg signed [6:0] y_r_0;
output reg signed [6:0] y_r_1;
output reg signed [6:0] y_r_2;
output reg signed [6:0] y_r_3;
output reg signed [6:0] y_r_4;
output reg signed [6:0] y_r_5;
output reg signed [6:0] y_r_6;
output reg signed [6:0] y_r_7;
output reg signed [6:0] y_i_0;
output reg signed [6:0] y_i_1;
output reg signed [6:0] y_i_2;
output reg signed [6:0] y_i_3;
output reg signed [6:0] y_i_4;
output reg signed [6:0] y_i_5;
output reg signed [6:0] y_i_6;
output reg signed [6:0] y_i_7;
//参数存储寄存器，存放旋转系数
//w_r_*表示旋转系数实部（cos值）
reg [3:0] w_r_0;
reg [3:0] w_r_1;
reg [3:0] w_r_2;
reg [3:0] w_r_3;
//w_i_*表示旋转系数虚部（sin值）
reg [3:0] w_i_0;
reg [3:0] w_i_1;
reg [3:0] w_i_2;
reg [3:0] w_i_3;
//中间寄存器
reg signed [11:0] x_r_tmp_0;
reg signed [11:0] x_r_tmp_1;
reg signed [11:0] x_r_tmp_2;
reg signed [11:0] x_r_tmp_3;
reg signed [11:0] x_r_tmp_4;
reg signed [11:0] x_r_tmp_5;
reg signed [11:0] x_r_tmp_6;
reg signed [11:0] x_r_tmp_7;
reg signed [11:0] x_i_tmp_0;
reg signed [11:0] x_i_tmp_1;
reg signed [11:0] x_i_tmp_2;
reg signed [11:0] x_i_tmp_3;
reg signed [11:0] x_i_tmp_4;
reg signed [11:0] x_i_tmp_5;
reg signed [11:0] x_i_tmp_6;
reg signed [11:0] x_i_tmp_7;
//中间保持寄存器，用来暂存中间寄存器的值，防止发生冲突
reg signed [11:0] x_r_tmp_last_0;
reg signed [11:0] x_r_tmp_last_1;
reg signed [11:0] x_r_tmp_last_2;
reg signed [11:0] x_r_tmp_last_3;
reg signed [11:0] x_r_tmp_last_4;
reg signed [11:0] x_r_tmp_last_5;
reg signed [11:0] x_r_tmp_last_6;
reg signed [11:0] x_r_tmp_last_7;
reg signed [11:0] x_i_tmp_last_0;
reg signed [11:0] x_i_tmp_last_1;
reg signed [11:0] x_i_tmp_last_2;
reg signed [11:0] x_i_tmp_last_3;
reg signed [11:0] x_i_tmp_last_4;
reg signed [11:0] x_i_tmp_last_5;
reg signed [11:0] x_i_tmp_last_6;
reg signed [11:0] x_i_tmp_last_7;
//状态机
reg [3:0] state_machine;
localparam state_start = 4'd0; //所有寄存器初始化
localparam state_input = 4'd1; //中间寄存器获取输入采样值
localparam state_s1 = 4'd2; //中间保持寄存器暂存数据过程
localparam state_s2 = 4'd3; //第一次蝶形乘法
localparam state_s3 = 4'd4; //中间保持寄存器暂存数据过程
localparam state_s4 = 4'd5; //第一次蝶形加法
localparam state_s5 = 4'd6; //中间保持寄存器暂存数据过程
localparam state_s6 = 4'd7; //第二次蝶形乘法
localparam state_s7 = 4'd9; //中间保持寄存器暂存数据过程
localparam state_s8 = 4'd10; //第二次蝶形加法
localparam state_s9 = 4'd11; //中间保持寄存器暂存数据过程
localparam state_s10 = 4'd12; //第三次蝶形乘法
localparam state_s11 = 4'd13; //中间保持寄存器暂存数据过程
localparam state_s12 = 4'd14; //第三次蝶形加法
localparam state_end = 4'd15; //输出计算结果
always @(posedge clk or negedge rst_n) begin
if(!rst_n) begin
w_r_0 = 4'd0;
w_r_1 = 4'd0;
w_r_2 = 4'd0;
w_r_3 = 4'd0;
w_i_0 = 4'd0;
w_i_1 = 4'd0;
w_i_2 = 4'd0;
w_i_3 = 4'd0;
x_r_tmp_0 <= 12'd0;
x_r_tmp_1 <= 12'd0;
x_r_tmp_2 <= 12'd0;
x_r_tmp_3 <= 12'd0;
x_r_tmp_4 <= 12'd0;
x_r_tmp_5 <= 12'd0;
x_r_tmp_6 <= 12'd0;
x_r_tmp_7 <= 12'd0;
x_i_tmp_0 <= 12'd0;
x_i_tmp_1 <= 12'd0;
x_i_tmp_2 <= 12'd0;
x_i_tmp_3 <= 12'd0;
x_i_tmp_4 <= 12'd0;
x_i_tmp_5 <= 12'd0;
x_i_tmp_6 <= 12'd0;
x_i_tmp_7 <= 12'd0;
x_r_tmp_last_0 <= 12'd0;
x_r_tmp_last_1 <= 12'd0;
x_r_tmp_last_2 <= 12'd0;
x_r_tmp_last_3 <= 12'd0;
x_r_tmp_last_4 <= 12'd0;
x_r_tmp_last_5 <= 12'd0;
x_r_tmp_last_6 <= 12'd0;
x_r_tmp_last_7 <= 12'd0;
x_i_tmp_last_0 <= 12'd0;
x_i_tmp_last_1 <= 12'd0;
x_i_tmp_last_2 <= 12'd0;
x_i_tmp_last_3 <= 12'd0;
x_i_tmp_last_4 <= 12'd0;
x_i_tmp_last_5 <= 12'd0;
x_i_tmp_last_6 <= 12'd0;
x_i_tmp_last_7 <= 12'd0;
y_r_0 <= 7'd0;
y_r_1 <= 7'd0;
y_r_2 <= 7'd0;
y_r_3 <= 7'd0;
y_r_4 <= 7'd0;
y_r_5 <= 7'd0;
y_r_6 <= 7'd0;
y_r_7 <= 7'd0;
y_i_0 <= 7'd0;
y_i_1 <= 7'd0;
y_i_2 <= 7'd0;
y_i_3 <= 7'd0;
y_i_4 <= 7'd0;
y_i_5 <= 7'd0;
y_i_6 <= 7'd0;
y_i_7 <= 7'd0;
state_machine <= state_start;
end
else case(state_machine)
state_start: begin
//输入旋转因子，其中cos值分别为10、7、0、-7
//因此，在遇到与w_r_3相乘时，需要加上负号
w_r_0 <= 4'd10;
w_r_1 <= 4'd7;
w_r_2 <= 4'sd0;
w_r_3 <= 4'd7;
//sin值分别为0、-7、-10、-7
//因此，在与w_i_1、w_i_2和w_i_3相乘时，需要加上负号
w_i_0 <= 4'd0;
w_i_1 <= 4'd7;
w_i_2 <= 4'd10;
w_i_3 <= 4'd7;
state_machine <= state_input;
end
state_input: begin
x_r_tmp_0 <= x_r_0;
x_r_tmp_1 <= x_r_4;
x_r_tmp_2 <= x_r_2;
x_r_tmp_3 <= x_r_6;
x_r_tmp_4 <= x_r_1;
x_r_tmp_5 <= x_r_5;
x_r_tmp_6 <= x_r_3;
x_r_tmp_7 <= x_r_7;
x_i_tmp_0 <= x_i_0;
x_i_tmp_1 <= x_i_4;
x_i_tmp_2 <= x_i_2;
x_i_tmp_3 <= x_i_6;
x_i_tmp_4 <= x_i_1;
x_i_tmp_5 <= x_i_5;
x_i_tmp_6 <= x_i_3;
x_i_tmp_7 <= x_i_7;
state_machine <= state_s1;
end
state_s1: begin
x_r_tmp_last_0 <= x_r_tmp_0;
x_r_tmp_last_1 <= x_r_tmp_1;
x_r_tmp_last_2 <= x_r_tmp_2;
x_r_tmp_last_3 <= x_r_tmp_3;
x_r_tmp_last_4 <= x_r_tmp_4;
x_r_tmp_last_5 <= x_r_tmp_5;
x_r_tmp_last_6 <= x_r_tmp_6;
x_r_tmp_last_7 <= x_r_tmp_7;
x_i_tmp_last_0 <= x_i_tmp_0;
x_i_tmp_last_1 <= x_i_tmp_1;
x_i_tmp_last_2 <= x_i_tmp_2;
x_i_tmp_last_3 <= x_i_tmp_3;
x_i_tmp_last_4 <= x_i_tmp_4;
x_i_tmp_last_5 <= x_i_tmp_5;
x_i_tmp_last_6 <= x_i_tmp_6;
x_i_tmp_last_7 <= x_i_tmp_7;
state_machine <= state_s2;
end
state_s2: begin
x_r_tmp_1 <= (x_r_tmp_last_1 * w_r_0 / 10) - (x_i_tmp_last_1 * w_i_0 / 10);
x_r_tmp_3 <= (x_r_tmp_last_3 * w_r_0 / 10) - (x_i_tmp_last_3 * w_i_0 / 10);
x_r_tmp_5 <= (x_r_tmp_last_5 * w_r_0 / 10) - (x_i_tmp_last_5 * w_i_0 / 10);
x_r_tmp_7 <= (x_r_tmp_last_7 * w_r_0 / 10) - (x_i_tmp_last_7 * w_i_0 / 10);
x_i_tmp_1 <= (x_r_tmp_last_1 * w_i_0 / 10) + (x_i_tmp_last_1 * w_r_0 / 10);
x_i_tmp_3 <= (x_r_tmp_last_3 * w_i_0 / 10) + (x_i_tmp_last_3 * w_r_0 / 10);
x_i_tmp_5 <= (x_r_tmp_last_5 * w_i_0 / 10) + (x_i_tmp_last_5 * w_r_0 / 10);
x_i_tmp_7 <= (x_r_tmp_last_7 * w_i_0 / 10) + (x_i_tmp_last_7 * w_r_0 / 10);
state_machine <= state_s3;
end
state_s3: begin
x_r_tmp_last_0 <= x_r_tmp_0;
x_r_tmp_last_1 <= x_r_tmp_1;
x_r_tmp_last_2 <= x_r_tmp_2;
x_r_tmp_last_3 <= x_r_tmp_3;
x_r_tmp_last_4 <= x_r_tmp_4;
x_r_tmp_last_5 <= x_r_tmp_5;
x_r_tmp_last_6 <= x_r_tmp_6;
x_r_tmp_last_7 <= x_r_tmp_7;
x_i_tmp_last_0 <= x_i_tmp_0;
x_i_tmp_last_1 <= x_i_tmp_1;
x_i_tmp_last_2 <= x_i_tmp_2;
x_i_tmp_last_3 <= x_i_tmp_3;
x_i_tmp_last_4 <= x_i_tmp_4;
x_i_tmp_last_5 <= x_i_tmp_5;
x_i_tmp_last_6 <= x_i_tmp_6;
x_i_tmp_last_7 <= x_i_tmp_7;
state_machine <= state_s4;
end
state_s4: begin
x_r_tmp_0 <= x_r_tmp_last_0 + x_r_tmp_last_1;
x_r_tmp_2 <= x_r_tmp_last_2 + x_r_tmp_last_3;
x_r_tmp_4 <= x_r_tmp_last_4 + x_r_tmp_last_5;
x_r_tmp_6 <= x_r_tmp_last_6 + x_r_tmp_last_7;
x_r_tmp_1 <= x_r_tmp_last_0 - x_r_tmp_last_1;
x_r_tmp_3 <= x_r_tmp_last_2 - x_r_tmp_last_3;
x_r_tmp_5 <= x_r_tmp_last_4 - x_r_tmp_last_5;
x_r_tmp_7 <= x_r_tmp_last_6 - x_r_tmp_last_7;
x_i_tmp_0 <= x_i_tmp_last_0 + x_i_tmp_last_1;
x_i_tmp_2 <= x_i_tmp_last_2 + x_i_tmp_last_3;
x_i_tmp_4 <= x_i_tmp_last_4 + x_i_tmp_last_5;
x_i_tmp_6 <= x_i_tmp_last_6 + x_i_tmp_last_7;
x_i_tmp_1 <= x_i_tmp_last_0 - x_i_tmp_last_1;
x_i_tmp_3 <= x_i_tmp_last_2 - x_i_tmp_last_3;
x_i_tmp_5 <= x_i_tmp_last_4 - x_i_tmp_last_5;
x_i_tmp_7 <= x_i_tmp_last_6 - x_i_tmp_last_7;
state_machine <= state_s5;
end
state_s5: begin
x_r_tmp_last_0 <= x_r_tmp_0;
x_r_tmp_last_1 <= x_r_tmp_1;
x_r_tmp_last_2 <= x_r_tmp_2;
x_r_tmp_last_3 <= x_r_tmp_3;
x_r_tmp_last_4 <= x_r_tmp_4;
x_r_tmp_last_5 <= x_r_tmp_5;
x_r_tmp_last_6 <= x_r_tmp_6;
x_r_tmp_last_7 <= x_r_tmp_7;
x_i_tmp_last_0 <= x_i_tmp_0;
x_i_tmp_last_1 <= x_i_tmp_1;
x_i_tmp_last_2 <= x_i_tmp_2;
x_i_tmp_last_3 <= x_i_tmp_3;
x_i_tmp_last_4 <= x_i_tmp_4;
x_i_tmp_last_5 <= x_i_tmp_5;
x_i_tmp_last_6 <= x_i_tmp_6;
x_i_tmp_last_7 <= x_i_tmp_7;
state_machine <= state_s6;
end
state_s6: begin
x_r_tmp_2 <= (x_r_tmp_last_2 * w_r_0 / 10) - (x_i_tmp_last_2 * w_i_0 / 10);
x_r_tmp_6 <= (x_r_tmp_last_6 * w_r_0 / 10) - (x_i_tmp_last_6 * w_i_0 / 10);
x_r_tmp_3 <= (x_r_tmp_last_3 * w_r_2 / 10) + (x_i_tmp_last_3 * w_i_2 / 10);
x_r_tmp_7 <= (x_r_tmp_last_7 * w_r_2 / 10) + (x_i_tmp_last_7 * w_i_2 / 10);
x_i_tmp_2 <= (x_i_tmp_last_2 * w_r_0 / 10) + (x_r_tmp_last_2 * w_i_0 / 10);
x_i_tmp_6 <= (x_i_tmp_last_6 * w_r_0 / 10) + (x_r_tmp_last_6 * w_i_0 / 10);
x_i_tmp_3 <= (x_i_tmp_last_3 * w_r_2 / 10) - (x_r_tmp_last_3 * w_i_2 / 10);
x_i_tmp_7 <= (x_i_tmp_last_7 * w_r_2 / 10) - (x_r_tmp_last_7 * w_i_2 / 10);
state_machine <= state_s7;
end
state_s7: begin
x_r_tmp_last_0 <= x_r_tmp_0;
x_r_tmp_last_1 <= x_r_tmp_1;
x_r_tmp_last_2 <= x_r_tmp_2;
x_r_tmp_last_3 <= x_r_tmp_3;
x_r_tmp_last_4 <= x_r_tmp_4;
x_r_tmp_last_5 <= x_r_tmp_5;
x_r_tmp_last_6 <= x_r_tmp_6;
x_r_tmp_last_7 <= x_r_tmp_7;
x_i_tmp_last_0 <= x_i_tmp_0;
x_i_tmp_last_1 <= x_i_tmp_1;
x_i_tmp_last_2 <= x_i_tmp_2;
x_i_tmp_last_3 <= x_i_tmp_3;
x_i_tmp_last_4 <= x_i_tmp_4;
x_i_tmp_last_5 <= x_i_tmp_5;
x_i_tmp_last_6 <= x_i_tmp_6;
x_i_tmp_last_7 <= x_i_tmp_7;
state_machine <= state_s8;
end
state_s8: begin
x_r_tmp_0 <= x_r_tmp_last_0 + x_r_tmp_last_2;
x_r_tmp_1 <= x_r_tmp_last_1 + x_r_tmp_last_3;
x_r_tmp_4 <= x_r_tmp_last_4 + x_r_tmp_last_6;
x_r_tmp_5 <= x_r_tmp_last_5 + x_r_tmp_last_7;
x_r_tmp_2 <= x_r_tmp_last_0 - x_r_tmp_last_2;
x_r_tmp_3 <= x_r_tmp_last_1 - x_r_tmp_last_3;
x_r_tmp_6 <= x_r_tmp_last_4 - x_r_tmp_last_6;
x_r_tmp_7 <= x_r_tmp_last_5 - x_r_tmp_last_7;
x_i_tmp_0 <= x_i_tmp_last_0 + x_i_tmp_last_2;
x_i_tmp_1 <= x_i_tmp_last_1 + x_i_tmp_last_3;
x_i_tmp_4 <= x_i_tmp_last_4 + x_i_tmp_last_6;
x_i_tmp_5 <= x_i_tmp_last_5 + x_i_tmp_last_7;
x_i_tmp_2 <= x_i_tmp_last_0 - x_i_tmp_last_2;
x_i_tmp_3 <= x_i_tmp_last_1 - x_i_tmp_last_3;
x_i_tmp_6 <= x_i_tmp_last_4 - x_i_tmp_last_6;
x_i_tmp_7 <= x_i_tmp_last_5 - x_i_tmp_last_7;
state_machine <= state_s9;
end
state_s9: begin
x_r_tmp_last_0 <= x_r_tmp_0;
x_r_tmp_last_1 <= x_r_tmp_1;
x_r_tmp_last_2 <= x_r_tmp_2;
x_r_tmp_last_3 <= x_r_tmp_3;
x_r_tmp_last_4 <= x_r_tmp_4;
x_r_tmp_last_5 <= x_r_tmp_5;
x_r_tmp_last_6 <= x_r_tmp_6;
x_r_tmp_last_7 <= x_r_tmp_7;
x_i_tmp_last_0 <= x_i_tmp_0;
x_i_tmp_last_1 <= x_i_tmp_1;
x_i_tmp_last_2 <= x_i_tmp_2;
x_i_tmp_last_3 <= x_i_tmp_3;
x_i_tmp_last_4 <= x_i_tmp_4;
x_i_tmp_last_5 <= x_i_tmp_5;
x_i_tmp_last_6 <= x_i_tmp_6;
x_i_tmp_last_7 <= x_i_tmp_7;
state_machine <= state_s10;
end
state_s10: begin
x_r_tmp_4 <= (x_r_tmp_last_4 * w_r_0 / 10) - (x_i_tmp_last_4 * w_i_0 / 10);
x_r_tmp_5 <= (x_r_tmp_last_5 * w_r_1 / 10) + (x_i_tmp_last_5 * w_i_1 / 10);
x_r_tmp_6 <= (x_r_tmp_last_6 * w_r_2 / 10) + (x_i_tmp_last_6 * w_i_2 / 10);
x_r_tmp_7 <= -(x_r_tmp_last_7 * w_r_3 / 10) + (x_i_tmp_last_7 * w_i_3 / 10);
x_i_tmp_4 <= (x_i_tmp_last_4 * w_r_0 / 10) + (x_r_tmp_last_4 * w_i_0 / 10);
x_i_tmp_5 <= (x_i_tmp_last_5 * w_r_1 / 10) - (x_r_tmp_last_5 * w_i_1 / 10);
x_i_tmp_6 <= (x_i_tmp_last_6 * w_r_2 / 10) - (x_r_tmp_last_6 * w_i_2 / 10);
x_i_tmp_7 <= -(x_i_tmp_last_7 * w_r_3 / 10) - (x_r_tmp_last_7 * w_i_3 / 10);
state_machine <= state_s11;
end
state_s11: begin
x_r_tmp_last_0 <= x_r_tmp_0;
x_r_tmp_last_1 <= x_r_tmp_1;
x_r_tmp_last_2 <= x_r_tmp_2;
x_r_tmp_last_3 <= x_r_tmp_3;
x_r_tmp_last_4 <= x_r_tmp_4;
x_r_tmp_last_5 <= x_r_tmp_5;
x_r_tmp_last_6 <= x_r_tmp_6;
x_r_tmp_last_7 <= x_r_tmp_7;
x_i_tmp_last_0 <= x_i_tmp_0;
x_i_tmp_last_1 <= x_i_tmp_1;
x_i_tmp_last_2 <= x_i_tmp_2;
x_i_tmp_last_3 <= x_i_tmp_3;
x_i_tmp_last_4 <= x_i_tmp_4;
x_i_tmp_last_5 <= x_i_tmp_5;
x_i_tmp_last_6 <= x_i_tmp_6;
x_i_tmp_last_7 <= x_i_tmp_7;
state_machine <= state_s12;
end
state_s12: begin
x_r_tmp_0 <= x_r_tmp_last_0 + x_r_tmp_last_4;
x_r_tmp_1 <= x_r_tmp_last_1 + x_r_tmp_last_5;
x_r_tmp_2 <= x_r_tmp_last_2 + x_r_tmp_last_6;
x_r_tmp_3 <= x_r_tmp_last_3 + x_r_tmp_last_7;
x_r_tmp_4 <= x_r_tmp_last_0 - x_r_tmp_last_4;
x_r_tmp_5 <= x_r_tmp_last_1 - x_r_tmp_last_5;
x_r_tmp_6 <= x_r_tmp_last_2 - x_r_tmp_last_6;
x_r_tmp_7 <= x_r_tmp_last_3 - x_r_tmp_last_7;
x_i_tmp_0 <= x_i_tmp_last_0 + x_i_tmp_last_4;
x_i_tmp_1 <= x_i_tmp_last_1 + x_i_tmp_last_5;
x_i_tmp_2 <= x_i_tmp_last_2 + x_i_tmp_last_6;
x_i_tmp_3 <= x_i_tmp_last_3 + x_i_tmp_last_7;
x_i_tmp_4 <= x_i_tmp_last_0 - x_i_tmp_last_4;
x_i_tmp_5 <= x_i_tmp_last_1 - x_i_tmp_last_5;
x_i_tmp_6 <= x_i_tmp_last_2 - x_i_tmp_last_6;
x_i_tmp_7 <= x_i_tmp_last_3 - x_i_tmp_last_7;
state_machine <= state_end;
end
state_end: begin
y_i_0 <= (x_i_tmp_0);
y_i_1 <= (x_i_tmp_1);
y_i_2 <= (x_i_tmp_2);
y_i_3 <= (x_i_tmp_3);
y_i_4 <= (x_i_tmp_4);
y_i_5 <= (x_i_tmp_5);
y_i_6 <= (x_i_tmp_6);
y_i_7 <= (x_i_tmp_7);
y_r_0 <= (x_r_tmp_0);
y_r_1 <= (x_r_tmp_1);
y_r_2 <= (x_r_tmp_2);
y_r_3 <= (x_r_tmp_3);
y_r_4 <= (x_r_tmp_4);
y_r_5 <= (x_r_tmp_5);
y_r_6 <= (x_r_tmp_6);
y_r_7 <= (x_r_tmp_7);
state_machine <= state_start;
end
default: begin
state_machine <= state_start;
end
endcase
end
endmodule接下来是testbench文件
`timescale 1ns / 1ns
`define clock_period 200
module FFT_8_tb;
reg clk;
reg rst_n;
reg signed [4:0] x_r_0;
reg signed [4:0] x_r_1;
reg signed [4:0] x_r_2;
reg signed [4:0] x_r_3;
reg signed [4:0] x_r_4;
reg signed [4:0] x_r_5;
reg signed [4:0] x_r_6;
reg signed [4:0] x_r_7;
reg signed [4:0] x_i_0;
reg signed [4:0] x_i_1;
reg signed [4:0] x_i_2;
reg signed [4:0] x_i_3;
reg signed [4:0] x_i_4;
reg signed [4:0] x_i_5;
reg signed [4:0] x_i_6;
reg signed [4:0] x_i_7;
wire signed [6:0] y_r_0;
wire signed [6:0] y_r_1;
wire signed [6:0] y_r_2;
wire signed [6:0] y_r_3;
wire signed [6:0] y_r_4;
wire signed [6:0] y_r_5;
wire signed [6:0] y_r_6;
wire signed [6:0] y_r_7;
wire signed [6:0] y_i_0;
wire signed [6:0] y_i_1;
wire signed [6:0] y_i_2;
wire signed [6:0] y_i_3;
wire signed [6:0] y_i_4;
wire signed [6:0] y_i_5;
wire signed [6:0] y_i_6;
wire signed [6:0] y_i_7;
FFT_8 FFT_8_Inst(
.clk(clk),
.rst_n(rst_n),
.x_r_0(x_r_0), //输入实部
.x_r_1(x_r_1),
.x_r_2(x_r_2),
.x_r_3(x_r_3),
.x_r_4(x_r_4),
.x_r_5(x_r_5),
.x_r_6(x_r_6),
.x_r_7(x_r_7),
.x_i_0(x_i_0), //输入虚部
.x_i_1(x_i_1),
.x_i_2(x_i_2),
.x_i_3(x_i_3),
.x_i_4(x_i_4),
.x_i_5(x_i_5),
.x_i_6(x_i_6),
.x_i_7(x_i_7),
.y_r_0(y_r_0), //输出实部
.y_r_1(y_r_1),
.y_r_2(y_r_2),
.y_r_3(y_r_3),
.y_r_4(y_r_4),
.y_r_5(y_r_5),
.y_r_6(y_r_6),
.y_r_7(y_r_7),
.y_i_0(y_i_0), //输出虚部
.y_i_1(y_i_1),
.y_i_2(y_i_2),
.y_i_3(y_i_3),
.y_i_4(y_i_4),
.y_i_5(y_i_5),
.y_i_6(y_i_6),
.y_i_7(y_i_7)
);
initial clk = 1;
always #(`clock_period/2) clk = ~clk;
initial begin
rst_n = 1'b0;
x_r_0 = 5'd0;
x_r_1 = 5'd0;
x_r_2 = 5'd0;
x_r_3 = 5'd0;
x_r_4 = 5'd0;
x_r_5 = 5'd0;
x_r_6 = 5'd0;
x_r_7 = 5'd0;
x_i_0 = 5'd0;
x_i_1 = 5'd0;
x_i_2 = 5'd0;
x_i_3 = 5'd0;
x_i_4 = 5'd0;
x_i_5 = 5'd0;
x_i_6 = 5'd0;
x_i_7 = 5'd0;
#(`clock_period*10 + 1);
rst_n = 1'b1;
x_r_0 = 5'b0_1110;
x_r_1 = 5'b0;
x_r_2 = 5'b0_0110;
x_r_3 = 5'b0;
x_r_4 = 5'b0_0101;
x_r_5 = 5'b0;
x_r_6 = 5'b0_1111;
x_r_7 = 5'b0;
x_i_0 = 5'd0;
x_i_1 = 5'd0;
x_i_2 = 5'd0;
x_i_3 = 5'd0;
x_i_4 = 5'd0;
x_i_5 = 5'd0;
x_i_6 = 5'd0;
x_i_7 = 5'd0;
#(`clock_period*50);
x_r_0 = 5'b0_0101;
x_r_1 = 5'b0_0101;
x_r_2 = 5'b0_0101;
x_r_3 = 5'b0_0101;
x_r_4 = 5'b0_0101;
x_r_5 = 5'b0_0101;
x_r_6 = 5'b0_0101;
x_r_7 = 5'b0_0101;
x_i_0 = 5'd0;
x_i_1 = 5'd0;
x_i_2 = 5'd0;
x_i_3 = 5'd0;
x_i_4 = 5'd0;
x_i_5 = 5'd0;
x_i_6 = 5'd0;
x_i_7 = 5'd0;
#(`clock_period*50);
$stop;
end
endmodule
来源：oschina
链接：https://my.oschina.net/u/4398140/blog/4268281