4位先行进位电路 logisim_数字集成电路的自动化设计作业—1
1、七人投票表决电路
Verilog代码如下：
module vote_7(
input [6:0] Vote,
input Reset,
output Pass);
integer i;
reg [2:0] vote_count;
always @(*) begin
if (Reset)
begin
vote_count = 3'd0;
end
else
begin
vote_count = 3'd0;
for (i=0;i<7;i=i+1)
begin
if (Vote[i] == 1) vote_count = vote_count + 1'd1;
end
end
end
assign Pass = (vote_count >= 3'd4) ? 1 : 0;
endmodule
测试代码如下：
//vote_7_tb
`timescale 1 ns/1 ns
module vote_7_tb();
reg [6:0] Vote;
reg Reset;
wire Pass;
vote_7 my_vote_7(
.Vote(Vote),
.Reset(Reset),
.Pass(Pass));
initial
begin
Vote=7'b0000001; Reset=0;
#5 Vote=7'b0000111; Reset=1;
#5 Vote=7'b0001111; Reset=0;
#5 Vote=7'b0011111; Reset=0;
#5 Vote=7'b0111111; Reset=0;
#5 Vote=7'b1111111; Reset=0;
#5 Vote=7'b1100111; Reset=0;
#5 Vote=7'b1100101; Reset=1;
#5 Vote=7'b1110101; Reset=0;
#5 $stop;
end
endmodule
仿真波形如下(清晰显示请点开放大)：
2、七人抢答电路
Verilog代码如下：
module responder(
input [6:0] vote,
input start,
input reset,
output reg nag,
output reg [2:0] rsp
);
always @(*) begin
if (reset)
begin
nag = 1'b0;
sp = 3'b0;
end
else if (start)
begin
case (vote)
7'b0000001: begin rsp = 3'b001; nag = 1'b0; end
7'b0000010: begin rsp = 3'b010; nag = 1'b0; end
7'b0000100: begin rsp = 3'b011; nag = 1'b0; end
7'b0001000: begin rsp = 3'b100; nag = 1'b0; end
7'b0010000: begin rsp = 3'b101; nag = 1'b0; end
7'b0100000: begin rsp = 3'b110; nag = 1'b0; end
7'b1000000: begin rsp = 3'b111; nag = 1'b0; end
default: begin rsp = 3'b000; nag = 1'b0; end
endcase
end
else if (vote)
nag = 1'b1;
end
endmodule
测试代码如下：
`timescale 1 ns/1 ns
module responder_tb();
reg [6:0] vote;
reg start;
reg reset;
wire nag;
wire [2:0] rsp;
responder my_responder(
.vote(vote),
.start(start),
.reset(reset),
.nag(nag),
.rsp(rsp)
);
initial
begin
reset=0; start=1; vote=7'b1000000;
#5 reset=1; start=1; vote=7'b1000000;
#5 reset=1; start=0; vote=7'b1000000;
#5 reset=0; start=0; vote=7'b1000000;
#5 reset=0; start=1; vote=7'b0000001;
#5 reset=0; start=1; vote=7'b0000010;
#5 reset=0; start=1; vote=7'b0000100;
#5 reset=0; start=1; vote=7'b0001000;
#5 reset=0; start=1; vote=7'b0010000;
#5 reset=0; start=1; vote=7'b0100000;
#5 reset=0; start=1; vote=7'b1000000;
#5 reset=0; start=1; vote=7'b1111001;
#10 $stop;
end
endmodule
仿真波形如下(清晰显示请点开放大)：
3、模为60的BCD码加法计数器
备注：这里将进位输出cout设置为1位，而不是题目给出的3位。
Verilog代码如下：
module counter_60(
input [7:0] data,
input load,
input reset,
input cin,
input clk,
output reg [7:0] qout,
output cout
);
always @(posedge clk)
begin
if (reset)
qout <= 0;
else if (load)
qout <= data;
else if (cin)
begin
if (qout[3:0] == 4'h9)//判断低位是否为9，是则
begin
qout[3:0] <= 0;//返回0
if (qout[7:4] == 4'h5)//并判断高位是否为5
qout[7:4] <= 0;
else
qout[7:4] <= qout[7:4] + 1'b1;//若高位不为5，则加1
end
else
qout[3:0] <= qout[3:0] + 1'b1;//若低位不为9，则加1
end
end
assign cout = ((qout == 8'h59) & cin) ? 1 : 0; //产生进位输出信号
endmodule
测试代码如下：
`timescale 1 ns/1 ns
module counter_60_tb();
reg [7:0] data;
reg reset, load, cin;
reg clk;
wire [7:0] qout;
wire cout;
counter_60 my_counter_60(
.data(data),
.reset(reset),
.load(load),
.cin(cin),
.clk(clk),
.qout(qout),
.cout(cout)
);
initial
begin
load=1'b0; reset=1'b0; data=8'h00; cin=1'b0;
#5 load=1'b0; reset=1'b1; data=8'h01; cin=1'b0;
#5 load=1'b0; reset=1'b0; data=8'h01; cin=1'b1;
#3 load=1'b1; reset=1'b0; data=8'h38; cin=1'b1;
#40 load=1'b0; reset=1'b0; data=8'h01; cin=1'b1;
#5 load=1'b0; reset=1'b0; data=8'h23; cin=1'b1;
#10 $stop;
end
initial
clk=0;
always
#2 clk = ~clk;
endmodule
仿真波形如下(清晰显示请点开放大)：
4、可逆计数器
备注：这里将进位输出cout设置为1位，而不是题目给出的3位。
Verilog代码如下：
module kn_cnt16(
input [3:0] data,
input clk,
input clr,
input set,
input en,
input updn,
output reg [3:0] qout,
output reg cout);
always @(posedge clk or posedge clr)
begin
if (clr) begin qout <= 0; cout <= 0; end
else if (set) begin qout <= data; cout <= 0; end
else if (en)
begin
case (updn)
1: begin
if (qout[3:0] == 4'b1111)
begin
qout[3:0] <= 4'b0000;
cout <= 1'b1;
end
else
begin
qout[3:0] <= qout[3:0] + 1'b1;
cout <= 1'b0;
end
end
0: begin
if (qout[3:0] == 4'b0000)
begin
qout[3:0] <= 4'b1111;
cout <= 1'b1;
end
else
begin
qout[3:0] <= qout[3:0] - 1'b1;
cout <= 1'b0;
end
end
endcase
end
end
endmodule
测试代码如下：
//kn_cnt16_tb
module kn_cnt16_tb();
reg [3:0] data;
reg clk;
reg clr, set, en, updn;
wire [3:0] qout;
wire cout;
kn_cnt16 my_kn_cnt16(
.data(data),
.clk(clk),
.clr(clr),
.set(set),
.en(en),
.updn(updn),
.qout(qout),
.cout(cout)
);
initial
begin
clk=1'b0; clr=1'b0; set=1'b0; en=1'b0; updn=1'b0; data=4'b0001;
#5 clr=1'b0; set=1'b1; en=1'b0; updn=1'b0; data=4'b0010;
#5 clr=1'b0; set=1'b0; en=1'b0; updn=1'b0; data=4'b0010;
#5 clr=1'b0; set=1'b0; en=1'b1; updn=1'b1; data=4'b0010;
#60 clr=1'b1; set=1'b0; en=1'b1; updn=1'b0; data=4'b0010;
#5 clr=1'b0; set=1'b0; en=1'b1; updn=1'b0; data=4'b1110;
#60 clr=1'b1; set=1'b0; en=1'b1; updn=1'b0; data=4'b0010;
#5 $stop;
end
always #2 clk = ~clk;
endmodule
仿真波形如下(清晰显示请点开放大)：
5、可变模计数器
备注：这里将进位输出cout设置为1位，而不是题目给出的3位。
Verilog代码如下：
module mchang100(
input [6:0] m,
input load,
input clr,
input clk,
output reg [6:0] qout,
output cout);
reg [6:0] md;
always @(posedge clk) begin
md <= m - 1'd1;
if (clr)
begin
qout[6:0] <= 6'd0;
end
else
begin
if (load)
begin
qout[6:0] <= md;
end
else
begin
if (qout[6:0] == md)
begin
qout[6:0] <= 6'd0;
end
else
begin
qout[6:0] <= qout[6:0] + 1'd1;
end
end
end
end
assign cout = (qout[6:0] == md) ? 1 : 0;
endmodule
测试代码如下：
// mchang100_tb
`timescale 1 ns/1 ns
module mchang100_tb();
reg [6:0] m;
reg load, clr;
reg clk;
wire [6:0] qout;
wire cout;
mchang100 my_mchang100(
.m(m),
.load(load),
.clr(clr),
.clk(clk),
.qout(qout),
.cout(cout)
);
initial
begin
clk=1'b0; m=7'b0001111; clr=1'b1; load=1'b0;
#5 m=7'b0001111; clr=1'b0; load=1'b1;
#5 m=7'b0001111; clr=1'b0; load=1'b0;
#50 m=7'b0000010; clr=1'b0; load=1'b1;
#5 m=7'b0000010; clr=1'b0; load=1'b0;
#10 m=7'b0001111; clr=1'b0; load=1'b0;
#5 $stop;
end
always
#1 clk = ~clk;
endmodule
仿真波形如下(清晰显示请点开放大)：
下图是15进制
下图是2进制
