module datapath( input clk, input [7:0] input_value, output reg [2:0] count ); reg [7:0] reg_input; reg [2:0] reg_count; reg [1:0] state; always @(posedge clk) begin reg_input <= input_value; state <= 0; reg_count <= 0; case(state) 0: begin if (reg_input != 0) begin state <= 1; end end 1: begin if (reg_input[0] == 1) begin reg_count <= reg_count + 1; count <= reg_count; end reg_input <= reg_input >> 1; state <= 0; end endcase end endmodule module fsm( input clk, input [2:0] count, output reg output_value ); always @(posedge clk) begin if (count == 4) begin output_value <= 1; end else begin output_value <= 0; end end endmodule module top( input clk, input [7:0] in, output wire out ); wire [2:0] count_dp; wire outf; datapath dp( .clk(clk), .input_value(in), .count(count_dp) ); fsm fsm( .clk(clk), .count(count_dp), .output_value(outf) ); assign out = outf; endmodule这个verilog代码在综合和实现上暂时没有出现问题,但无法生成比特流,请问是哪里出了问题?如何修改?
时间: 2024-02-25 17:54:10 浏览: 29
这段代码出现问题的原因可能是综合工具优化了代码,导致某些信号被优化掉了,无法生成比特流。为了解决这个问题,可以尝试在代码中添加一些锁定信号,避免被优化掉。
以下是修改后的代码,添加了一些锁定信号,以确保所有信号都能被正确综合:
```verilog
module datapath(
input clk,
input [7:0] input_value,
output reg [2:0] count
);
reg [7:0] reg_input;
reg [2:0] reg_count;
reg [1:0] state;
reg lock1, lock2;
always @(posedge clk) begin
if (lock1) begin
lock1 <= 0;
end else if (lock2) begin
lock2 <= 0;
end else begin
lock1 <= 1;
reg_input <= input_value;
state <= 0;
reg_count <= 0;
lock2 <= 1;
case(state)
0: begin
if (reg_input != 0) begin
state <= 1;
end
end
1: begin
if (reg_input[0] == 1) begin
reg_count <= reg_count + 1;
count <= reg_count;
end
reg_input <= reg_input >> 1;
state <= 0;
end
endcase
end
end
endmodule
module fsm(
input clk,
input [2:0] count,
output reg output_value
);
reg lock;
always @(posedge clk) begin
if (lock) begin
lock <= 0;
end else begin
lock <= 1;
if (count == 4) begin
output_value <= 1;
end else begin
output_value <= 0;
end
end
end
endmodule
module top(
input clk,
input [7:0] in,
output wire out
);
wire [2:0] count_dp;
wire outf;
datapath dp(
.clk(clk),
.input_value(in),
.count(count_dp)
);
fsm fsm(
.clk(clk),
.count(count_dp),
.output_value(outf)
);
assign out = outf;
endmodule
```
在上面的代码中,添加了两个锁定信号`lock1`和`lock2`,以确保在一个时钟周期内只有一个操作被执行。此外,修改了`if`语句的结构,以避免综合工具将其优化掉。现在,这个代码应该能够成功生成比特流了。
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