modelsim中关于$display的使用举例

wsz561208

做了几年了$display,第一次使用，所以赶紧记下来，方便以后在modelsim仿真的时候使用。

`timescale 1ns/1ns    //设置时钟精度
module comparetop;

wire
[3:0]
b1,b2,c1,c2;
reg
[3:0]
a;
reg
clk;

initial
begin

clk = 0;

forever #50 clk = ~clk;
end


initial
begin

a = 4'h3;

$display("__________");

#100 a = 4'h7;

$display("__________");

#100 a = 4'hf;

$display("__________");

#100 a = 4'ha;

$display("__________");

#100 a = 4'h2;

$display("__________");

#100 $display("__________");

$stop;
end

non_blocking non_blocking(clk,a,b2,c2);
blocking
blocking(clk,a,b1,c1);

endmodule


`timescale 1ns/1ns    //设置时钟精度
module blocking(
input
clk,
input
[3:0]
a,
output
reg
[3:0]
b,c
);


always@(posedge clk)
begin

b = a ;

c = b ;

$display("blocking:a=%d,b=%d,c=%d.",a,b,c);
end

endmodule


`timescale 1ns/1ns    //设置时钟精度
module non_blocking(
input
clk,
input
[3:0]
a,
output
reg
[3:0]
b,c
);


always@(posedge clk)
begin

b <= a ;

c <= b ;

$display("non_blocking:a=%d,b=%d,c=%d.",a,b,c);
end

endmodule


在modelsim中Transcript中的显示如下：

# Refreshing F:\wsz\test\20151023\comparetop\work.comparetop
# Loading work.comparetop
# Refreshing F:\wsz\test\20151023\comparetop\work.non_blocking
# Loading work.non_blocking
# Refreshing F:\wsz\test\20151023\comparetop\work.blocking
# Loading work.blocking
# __________
# blocking:a= 3,b= 3,c= 3.
# non_blocking:a= 3,b= x,c= x.
# __________
# blocking:a= 7,b= 7,c= 7.
# non_blocking:a= 7,b= 3,c= x.
# __________
# blocking:a=15,b=15,c=15.
# non_blocking:a=15,b= 7,c= 3.
# __________
# blocking:a=10,b=10,c=10.
# non_blocking:a=10,b=15,c= 7.
# __________
# blocking:a= 2,b= 2,c= 2.
# non_blocking:a= 2,b=10,c=15.
# __________
# Break in Module comparetop at F:/wsz/test/20151023/comparetop/comparetop.v line 28
# Simulation Breakpoint: Break in Module comparetop at F:/wsz/test/20151023/comparetop/comparetop.v line 28
# MACRO ./sim.do PAUSED at line 15

wsz561208

$display相关的使用问题可以参考verilog相关标准文档。

ralphtwtw

$display相关的使用问题