Fsm1 Fsm1

This is a Moore state machine with two states, one input, and one output. Implement this state machine. Notice that the reset state is B.

This exercise is the same as fsm1s, but using asynchronous reset.

 

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;

    always @(*) begin    // This is a combinational always block
         // State transition logic
        state <= next_state;
    end

    always @(posedge clk, posedge areset) begin    // This is a sequential always block
        // State flip-flops with asynchronous reset
        if(areset)
            next_state <= B;
        else case (next_state)
            B:
                if(in == 0)
                	next_state <= A;
            else 
                next_state <= B;
            A: if(in == 0)
                next_state <= B;
            else
                next_state <= A;
            default:
            	next_state <= B; 
        endcase
    end

    // Output logic
    // assign out = (state == ...);
    assign out = (state == A) ? 1'b0 : 1'b1;
endmodule