半加器

module  half_qwer(a,b,cout,sum);
//半加器设计
input a,b;
output cout,sum;
assign sum = a^b;
assign cout = a
endmodule

全加器

• 利用for循环进行级联设计 数据流

`timescale 1ns / 1ps
module qwe(a,b,cin,cout,sum);//一位
input a,b,cin;
output sum,cout;
assign sum = a^b^cin;
assign cout = (a&b)|(a&cin)|(b
endmodule
//四位全加器
module asdfg(sum,cout,a,b,cin);
input[3:0] a,b;
input cin;
output[3:0] sum;
output cout;
assign {cout,sum} = a+b+cin;
endmodule
================四位全加器仿真===================
	initial begin
		// Initialize Inputs
		a = 0;b = 0;cin = 0;#100;
		// Add stimulus here
		repeat(10000) #100 {a,b,cin} = {a,b,cin}+1;
	end
//八位全加器
module qwer(a,b,cin,sum,cout);
parameter SIZE	= 8;
input[SIZE-1:0]a,b;
input cin;
output[SIZE-1:0] sum;
output cout;
wire[SIZE:0] c;
assign c[0] = cin;
generate //for循环级联8位
	genvar i;
	for(i=0;i<SIZE;i=i+1)
		begin : add
            qwe fi(a[i],b[i],c[i],sum[i],c[i+1]);//模块调用
		end
endgenerate
assign cout = c[SIZE];
endmodule

2-4译码器

module fgvh(A,Q);
input[1:0] A;//两位输入
output reg[3:0] Q;//四位输出
always @(A)
begin
	case(A)
	2'b00  : Q[3:0] =4'b1110;
	2'b01  : Q[3:0] =4'b1101;
	2'b10  : Q[3:0] =4'b1011;
	2'b11  : Q[3:0] =4'b0111;
	endcase
end
endmodule
=========================建议使用下面的方法=============================
module qwe(A,Q);
//2-4译码器  for循环
input[1:0] A;
output reg[3:0] Q;
integer i;
always @(A)
begin
	Q = 4'b1111;
	for(i=0;i<=3;i=i+1)
		if(A==i)
			Q[i] = 0;
		else
			Q[i] = 1;
end
endmodule
============================================================
//仿真激励代码
initial begin
		// Initialize Inputs
		A = 0;
		#100;
		forever begin A=A+1;#100;end
	end

3-8译码器

module sanba(A,Q);
//3-8译码器  法一（不推荐）
input[2:0] A;
output reg[7:0] Q;
always @(A)
begin 
	case(A)
	3'b000:Q=8'b1111_1110;
	3'b001:Q=8'b1111_1101;
	3'b010:Q=8'b1111_1011;
	3'b011:Q=8'b1111_0111;
	3'b100:Q=8'b1110_1111;
	3'b101:Q=8'b1101_1111;
	3'b110:Q=8'b1011_1111;
	3'b111:Q=8'b0111_1111;
	endcase
end
endmodule
======================推荐使用下面方法==========================
module qwerttgy(A,Q);
//3-8译码器  for循环  方法二（推荐）
input[2:0] A;
output reg[7:0] Q;
integer i;
always @(A)
begin
	Q=8'b1111_1111;
	for(i=0;i<=7;i=i+1)
		if(A==i)
			Q[i] = 0;
		else
			Q[i] = 1;
end
endmodule

编码器

module bvhk(A,Q);
input[3:0] A;
output reg[1:0] Q;
always@(A)
	begin
	case(A)
	4'b0001:begin Q=2'b00;end
	4'b0010:begin Q=2'b01;end
	4'b0100:begin Q=2'b10;end
	4'b1000:begin Q=2'b11;end
	default:begin Q = 2'bx;end
	endcase
	end
endmodule
=============仿真==============
		A = 1;
		#100;
		forever begin A=A*2;#100;end

分频器

module aerwyghz(fout,clk,res);
//分频器
input clk,res;
output reg fout;
reg[29:0] counter;
always@(posedge clk)
begin
	if(res)begin counter<=0;fout<=0; end
	else begin 
        if(counter==24)//50分频，10分频counter==9
			begin 
			counter<=0;fout<=~fout;
			end
			else begin
			counter <=counter+1;
			end
	end
end
endmodule
==================分频器仿真=======================
		clk = 0;res = 1;
		clk=1;#100;
		res=0;
		forever #10 clk = !clk;

PWM

module ryuj(clk,res,pwm,fout);
input clk,res;
input[3:0]pwm;
output reg fout;
reg[30:0] j;
always@(posedge clk or negedge res)
begin
	if(res==0) begin j<=0;fout<=0;end
	else begin 
		if(j==9) begin j<=0;end
			else j<=j+1;
			if(j<pwm)fout<=1;
			else fout<=0;
			end
end
endmodule
========================仿真========================
	initial begin
		// Initialize Inputs
		clk = 0;pwm = 0;res = 1;res = 0;#100;
		res = 1;
		pwm = 8;
		repeat(100) begin #100; clk = ~clk;end
	end

七段数码管译码器*

`timescale 1ns / 1ps
module rtyu(bcd_out,bit_S,indec,res);
input [3:0]indec;
input res;
output reg[3:0] bit_s;
output reg[6:0]bcd_out;
always@(res,indec)
begin
    if(!res)begin bcd_out=7'bx;bit_s=4'b1111;end
	else begin
		bit_s=4'b1110;
		case(indec)//共阳数码管  dp、g、f、e、d、c、b、a
		0:bcd_out=7'hc0;//1100_0000
		1:bcd_out=7'hf9;//1111_1001
		2:bcd_out=7'ha4;//1010_0100
		3:bcd_out=7'hb0;//1011_0000
		4:bcd_out=7'h99;//1001_1001
		5:bcd_out=7'h92;//1001_0010
		6:bcd_out=7'h82;//1000_0010
		7:bcd_out=7'hf8;//1111_1000
		8:bcd_out=7'h80;//1000_0000
		9:bcd_out=7'h90;//1001_0000
		endcase
	end
end
endmodule
============仿真代码================
		indec = 0;
		res = 1;#50;
		repeat(10)begin#100 indec=indec+1;end
		res=0;indec=0;
		repeat(10)begin#100 indec=indec+1;end

流水灯

module jhfgx(clk,led,res);
output reg[7:0]led;
input clk,res;
reg[29:0] counter;
always@(posedge clk)
begin 
if(res)begin counter<=0;led<=8'b0000_0001;end
else begin
if(led==0) led<=8'b0000_0001;
	if(counter>=25_000_00)
		begin counter<=0;
		led<=led<<1;
		end
		else counter<=counter+1;
end
end
endmodule
=====================仿真代码=====================
	initial begin
		// Initialize Inputs
		clk = 0;res = 1;clk=1;#100;
		res = 0;
		forever begin #25 clk=~clk;end
	end