| module fsm ( | |
| clock, | |
| reset, | |
| req, | |
| gnt | |
| ); | |
| input clock,reset; | |
| inout [1:0] req ; | |
| output [1:0] gnt ; | |
| wire clock,reset; | |
| wire [1:0] req ; | |
| reg [1:0] gnt ; | |
| parameter SIZE = 3 ; | |
| parameter IDLE = 3'b001,GNT0 = 3'b010,GNT1 = 3'b100,GNT2 = 3'b101,GNT3 = 3'b111; | |
| reg [SIZE-1:0] state; | |
| reg [SIZE-1:0] next_state; | |
| always @ (posedge clock) | |
| begin : FSM | |
| if (reset == 1'b1) begin | |
| state <= #1 IDLE; | |
| gnt[0] <= 0; | |
| gnt[1] <= 0; | |
| end else | |
| case(state) | |
| IDLE : if (req[0] == 1'b1) begin | |
| state <= #1 GNT0; | |
| `ifndef BUG | |
| gnt[0] <= 1; | |
| `else | |
| gnt[0] <= 1'bZ; | |
| `endif | |
| end else if (req[1] == 1'b1) begin | |
| gnt[1] <= 1; | |
| state <= #1 GNT0; | |
| end else begin | |
| state <= #1 IDLE; | |
| end | |
| GNT0 : if (gnt[1] == 1'b1) begin | |
| state <= #1 GNT0; | |
| end else begin | |
| gnt[1] <= 0; | |
| state <= #1 IDLE; | |
| end | |
| GNT1 : if (req[1] == 1'b1) begin | |
| state <= #1 GNT2; | |
| gnt[1] <= req[1]; | |
| end | |
| GNT2 : if (gnt[0] == 1'b1) begin | |
| state <= #1 GNT1; | |
| gnt[1] <= req[1]; | |
| end | |
| default : state <= #1 IDLE; | |
| endcase | |
| end | |
| endmodule | |
| module fsm2 ( | |
| clock, | |
| reset, | |
| req, | |
| gnt | |
| ); | |
| input clock,reset; | |
| inout [1:0] req ; | |
| output [1:0] gnt ; | |
| wire clock,reset; | |
| wire [1:0] req ; | |
| reg [1:0] gnt ; | |
| parameter SIZE = 3 ; | |
| parameter IDLE = 3'b001,GNT0 = 3'b010,GNT1 = 3'b100,GNT2 = 3'b101,GNT3 = 3'b111; | |
| reg [SIZE-1:0] state; | |
| reg [SIZE-1:0] next_state; | |
| always @ (posedge clock) | |
| begin : FSM | |
| if (reset == 1'b1) begin | |
| state <= #1 IDLE; | |
| gnt[0] <= 0; | |
| gnt[1] <= 0; | |
| end else | |
| case(state) | |
| IDLE : if (req[0] == 1'b1) begin | |
| state <= #1 GNT0; | |
| `ifndef BUG | |
| gnt[0] <= 1; | |
| `else | |
| gnt[0] <= 1'bZ; | |
| `endif | |
| end else if (req[1] == 1'b1) begin | |
| gnt[1] <= 1; | |
| state <= #1 GNT0; | |
| end else begin | |
| state <= #1 IDLE; | |
| end | |
| GNT0 : if (gnt[1] == 1'b1) begin | |
| state <= #1 GNT0; | |
| end else begin | |
| gnt[1] <= 0; | |
| state <= #1 IDLE; | |
| end | |
| GNT1 : if (req[1] == 1'b1) begin | |
| state <= #1 GNT2; | |
| gnt[1] <= req[1]; | |
| end | |
| GNT2 : if (gnt[0] == 1'b1) begin | |
| state <= #1 GNT1; | |
| gnt[1] <= req[1]; | |
| end | |
| default : state <= #1 IDLE; | |
| endcase | |
| end | |
| endmodule | |
| module top ( | |
| input clk, | |
| input rst, | |
| input a, | |
| input b, | |
| output g0, | |
| output g1 | |
| ); | |
| wire [1:0] g ; | |
| wire [1:0] r ; | |
| fsm u_fsm ( .clock(clk), | |
| .reset(rst), | |
| .req(r), | |
| .gnt(g)); | |
| assign g0 = g[0]; | |
| assign g1 = g[1]; | |
| assign r[0] = a; | |
| assign r[1] = b; | |
| endmodule |