一个状态机程序老报错
小弟不才，用三段输出锁存式状态机 写一个序列检测程序，检测101序列。我的状态可能有冗余，暂时不要关心这些~我想问的是，为什么报错，程序如下module sq_scan (
input dat,clk,rst_n,
outputreg led);
parameter S0 = 4'b 0001,
S1 = 4'b 0010,
S2 = 4'b 0100,
S3 = 4'b 1000;
reg state,next;
always @(posedge clk or negedge rst_n)
if (!rst_n) state <= S0 ;
else state <= next;
always @(state or dat)begin/Error (10028): Can't resolve multiple constant drivers for net "led" at sq_scan.v(14)
next = 4'bx;
led= 1'b0;
case(state)
S0: if(dat) next = S1;
else next = S0;
S1: if(dat) next = S1;
else next = S2;
S2: if(dat) next = S3;
else next = S0;
S3: if(dat) next = S1;
else next = S2;
endcase
end
always @(posedge clk or negedge rst_n)
if (!rst_n) begin
led <= 1'b0;
end
else begin
case (next)
S0,S1,S2: led <= 1'b0 ;
S3 : led <= 1'b1;
endcase
end
endmodule
程序老是报错，错误已经标注在报错行的后面了。可是我觉得那句always就应该把涉及状态转变的变量都作为敏感变量啊？请大侠指点一二 两个always里都放了
led <= 1'b0;
这个是不允许的
估计LZ可能应该吧
always @(state or dat)中的句子给删了
PS:编译器已经说的非常明白了，led不能多处同时赋值 回复【1楼】syuanwang昙花公公
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正解！！！多谢多谢。3 always 块状态机，状态转移的那个逻辑里不能出现输出~~~和2 always块搞混了~
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