1.原理

2.代码

2.1 complex_fsm.v

module complex_fsm(input wire  	sys_clk			,input wire 		sys_rst_n		,input wire 		pi_money_half	,input wire 		pi_money_one	,output reg 		po_cola			,output reg 		po_money
);parameter 	IDLE=		5'b00001,HALF=		5'b00010,ONE=		5'b00100,ONE_HALF=	5'b01000,TWO=		5'b10000;wire [1:0] pi_money;
reg [4:0] state;assign pi_money={pi_money_one,pi_money_half};always@(posedge sys_clk or negedge sys_rst_n)if (sys_rst_n==1'b0)state <=IDLE;else case(state)IDLE:	if(pi_money==2'b01)state<=HALF;else if(pi_money==2'b10)state<=ONE;elsestate<=IDLE;HALF:	if(pi_money==2'b01)state<=ONE;else if(pi_money==2'b10)state<=ONE_HALF;elsestate<=HALF;ONE:	if(pi_money==2'b01)state<=ONE_HALF;else if(pi_money==2'b10)state<=TWO;elsestate<=ONE;ONE_HALF:if(pi_money==2'b01)state<=TWO;else if(pi_money==2'b10)state<=IDLE;elsestate<=ONE_HALF;TWO:	if(pi_money==2'b01)state<=IDLE;else if(pi_money==2'b10)state<=IDLE;elsestate<=IDLE;default:state<=IDLE;endcasealways@(posedge sys_clk or negedge sys_rst_n)if (sys_rst_n==1'b0)po_cola<=1'b0;else if(((state==ONE_HALF)&&(pi_money==2'b10))||((state==TWO)&&(pi_money==2'b01))||((state==TWO)&&(pi_money==2'b10)))po_cola<=1'b1;elsepo_cola<=1'b0;always@(posedge sys_clk or negedge sys_rst_n)if (sys_rst_n==1'b0)po_money<=1'b0;else if((state==TWO)&&(pi_money==2'b10))po_money<=1'b1;elsepo_money<=1'b0;endmodule

2.2 tb_complex_fsm.v

`timescale 1ns/1ns
module tb_complex_fsm();reg sys_clk;
reg sys_rst_n;
reg pi_money_half;
reg pi_money_one	;
reg random_money;wire po_cola	;		
wire po_money	;initial beginsys_clk=1'b1;sys_rst_n<=1'b0;#20sys_rst_n<=1'b1;endalways #10 sys_clk=~sys_clk;always@(posedge sys_clk or negedge sys_rst_n)if (sys_rst_n==1'b0)random_money<=1'b0;else random_money<={$random}%2;always@(posedge sys_clk or negedge sys_rst_n)if (sys_rst_n==1'b0)pi_money_half<=1'b0;else pi_money_half<=random_money;always@(posedge sys_clk or negedge sys_rst_n)if (sys_rst_n==1'b0)pi_money_one<=1'b0;else pi_money_one<=~random_money;complex_fsm complex_fsm_inst(.sys_clk		(sys_clk)	,.sys_rst_n		(sys_rst_n),.pi_money_half	(pi_money_half),.pi_money_one	(pi_money_one),.po_cola		(po_cola)	,.po_money       (po_money)
);endmodule