蓄水池问题

S3 S2 S1 

例如：000  代表 无水 ，需要使FR3, FR2, FR1 都打开（111）

S3 S2 S1     FR3 FR2 FR1

000                  111

001                011

011               001

111               000

fr代表水变深为0 ，水变少为1

module top_module (input clk,input reset,input [3:1] s,output fr3,output fr2,output fr1,output dfr
); parameter B_S1 = 3'b000,  B_S1_S2 = 3'b001,B_S2_S3 = 3'b011,A_S3 = 3'b111;reg [2:0] state;reg [2:0] next_state;always@ (posedge clk) beginstate <= next_state;   //next_state 变化较快end always@ (*)if(reset)next_state <= B_S1;else case({s[3], s[2], s[1]})B_S1: if(s[1]+s[2]+s[3] == 0)   next_state <= B_S1;else  next_state <= B_S1_S2;B_S1_S2: if(s[1]&& s[2] && ~s[3] )  next_state <= B_S2_S3;else if(s[1]+s[2]+s[3] == 0)next_state <= B_S1;elsenext_state <= B_S1_S2;B_S2_S3:if(s[1] & s[2] && s[3]) next_state <= A_S3;else if(s[1] && ~s[2] && ~s[3])   next_state <= B_S1_S2;elsenext_state <= B_S2_S3;A_S3:     if(&s) next_state <= A_S3;else  next_state <= B_S2_S3;default: next_state <= B_S1;endcasealways@ (posedge clk)if(reset) begin{fr3, fr2, fr1} <= 3'b111;endelse case ({s[3], s[2], s[1]})B_S1: {fr3, fr2, fr1} <= 3'b111;B_S1_S2: {fr3, fr2, fr1} <= 3'b011;B_S2_S3: {fr3, fr2, fr1} <= 3'b001;A_S3: {fr3, fr2, fr1} <= 3'b000;default:{fr3, fr2, fr1} <= 3'b111;endcasealways@ (posedge clk)if(reset)  dfr <= 1;else if(state < next_state)  //水变深dfr <= 0;else if(state > next_state)   dfr <= 1;else dfr <= dfr;endmodule