Verilog:转换的整数不适用于For循环

时间:2014-03-17 22:42:02

标签: for-loop binary verilog

我在Verilog中编写一个接受二进制值的程序,将其转换为Integer,然后输出“Hello,World!”这么多次。

但是,每当我运行程序时,都没有Hello,World的显示。这是代码:

// Internal Variable
wire [0:4] two_times_rotate;

// Multiply the rotate_imm by two (left shift)
assign {two_times_rotate} = rotate_imm << 1;
integer i, times_rotated;

// Convert two_times_rotate into an integer
always @( two_times_rotate )
begin
  times_rotated = two_times_rotate;
end

initial 
begin

for (i = 0; i < times_rotated; i = i + 1)
begin
  $display("Hello, World");
end

end

assign {out} = in;
 endmodule

我尝试使用以下for循环:

for (i = 0; i < 7; i = i + 1)

这一次打印Hello,World七次,就像它应该的那样。

*的 更新 *

到目前为止,这是我的代码中的内容。我试图做一个比较比较的比特。它仍然无法正常工作。如何在for循环的比较中使用它完全从二进制转换为整数?

 module immShifter(input[0:31] in, input[0:3] rotate_imm, 
              output[0:31] out);

 // Internal Variable
 wire [0:4] two_times_rotate;
 reg [0:4] i;

 // Multiply the rotate_imm by two (left shift)
 assign {two_times_rotate} = rotate_imm << 1;
 integer times_rotated, for_var;

 // Convert two_times_rotate into an integer
 always @( two_times_rotate )
 begin
    assign{times_rotated} = two_times_rotate;
 end

 initial 
 begin

 assign{i} = 5'b00000;
 assign{for_var} = times_rotated;
 for (i = 5'b00000; i < times_rotated; i = i + 5'b00001)
 begin
   $display("Hello, World");
 end

 end

 assign {out} = in;
endmodule 

1 个答案:

答案 0 :(得分:1)

在评估for循环时,

times_rotated在时间0是32'bX。 for循环正在检查i < 32'bX,这是错误的。


根据您的更新,这可能是您的意图:

module immShifter( input [31:0] in, input [3:0] rotate_imm, output [31:0] out );
  integer i, times_rotated;
  always @*
  begin
    times_rotated = rotate_imm << 1;
    for (i = 0; i < times_rotated; i++)
      $display("Hello, World");
    $display(""); // empty line as separate between changes to rotate_imm
  end
  assign out = in;
endmodule