理论解读

写几段式状态机？

设计实战

两种state的FSM（异步复位）

实现下图所示的摩尔状态机，复位为异步复位。

代码实现：

module top_module(
    input clk,
    input areset,    // Asynchronous reset to state B
    input in,
    output out);//  

    parameter A=0, B=1; 
    reg state, next;
    
    // State transition logic
    always@(*)begin    // This is a combinational always block
        case(state)
			A: next = in ? A : B;
			B: next = in ? B : A;
        endcase
    end

    // State flip-flops with asynchronous reset
    always @(posedge clk or posedge areset) begin    // This is a sequential always block
        if(areset == 1'b1)begin
            state <= B;
        end else begin
            state <= next;
        end
    end

    // Output logic
    assign out = (state == B);

endmodule

• 验证结果