状态机的练习：按键控制led灯

设计思路：

三个按键控制led输出。

三个按键经过滤波(消抖)，产生三个按键标志信号。

三个led数据的产生模块（流水，跑马，闪烁模块），分别产生led信号。

这六路信号（三路按键信号，三路led信号），接入state_led_ctrl模块，进行led_out的控制。

状态机：

模块框图：

代码：

/*1位按键消抖
*/ 
module key_filter (input       wire            sys_clk     ,input       wire            sys_rst_n   ,input       wire            key_in      ,output      reg             key_flag    
);// 参数定义parameter   MAX_CNT_10MS = 500_000   ;localparam  IDLE         = 4'b0001   ,FILTER_UP    = 4'b0010   ,SAMPLING     = 4'b0100   ,FILTER_BACK  = 4'b1000   ;// reg signal define reg                 key_in_r1 ;  reg                 key_in_r2 ;reg     [18:0]      cnt_core  ;reg     [3:0]       state_c   ;reg     [3:0]       state_n   ;// wire signal define wire                nege                  ;wire                pose                  ;wire                IDLEtoFILTER_UP       ;wire                FILTER_UPtoIDLE       ;wire                FILTER_UPtoSAMPLING   ;wire                SAMPLINGtoFILTER_BACK ;wire                FILTER_BACKtoIDLE     ;wire                filter_done           ; /******************************************************************/// reg                 key_in_r1 ; always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) key_in_r1 <= 1'b1 ;elsekey_in_r1 <= key_in ;end // reg                 key_in_r2 ;always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) key_in_r2 <= 1'b1 ;elsekey_in_r2 <= key_in_r1 ;end // wire                nege      ;assign  nege = ~key_in_r1 &&  key_in_r2 ;// wire                pose      ;  assign  pose =  key_in_r1 && ~key_in_r2 ;// reg     [3:0]       state_c   ;always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) state_c <= IDLE ;elsestate_c <= state_n ;end// reg     [3:0]       state_n   ;always @(*) begincase(state_c)IDLE      : if(IDLEtoFILTER_UP)state_n = FILTER_UP ;else state_n = IDLE ;FILTER_UP : if(FILTER_UPtoIDLE)state_n = IDLE ;else if(FILTER_UPtoSAMPLING)state_n = SAMPLING ;else state_n = FILTER_UP ;SAMPLING  : if(SAMPLINGtoFILTER_BACK)state_n = FILTER_BACK ;else state_n = SAMPLING ;FILTER_BACK:if(FILTER_BACKtoIDLE)state_n = IDLE ;elsestate_n = FILTER_BACK ;default   :     state_n = IDLE ;endcaseendassign  IDLEtoFILTER_UP         = (state_c == IDLE)       && (nege) ;assign  FILTER_UPtoIDLE         = (state_c == FILTER_UP)  && (pose) ;assign  FILTER_UPtoSAMPLING     = (state_c == FILTER_UP)  && (filter_done) ;assign  SAMPLINGtoFILTER_BACK   = (state_c == SAMPLING)   && (pose) ;assign  FILTER_BACKtoIDLE       = (state_c == FILTER_BACK)&& (filter_done) ;// reg     [18:0]      cnt_core  ;always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) cnt_core <= 19'd0 ;elsecase (state_c)IDLE       :cnt_core <= 19'd0 ; FILTER_UP  :if(filter_done)cnt_core <= 19'd0 ;else cnt_core <= cnt_core + 1'b1 ;SAMPLING   :cnt_core <= 19'd0 ; FILTER_BACK:if(filter_done)cnt_core <= 19'd0 ;else cnt_core <= cnt_core + 1'b1 ;default    :    cnt_core <= 19'd0 ;endcaseend// wire                filter_doneassign  filter_done = (cnt_core == MAX_CNT_10MS - 1) ;// output reg key_flagalways @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) key_flag <= 1'b0 ;else if(FILTER_UPtoSAMPLING)key_flag <= ~key_in_r2 ;else key_flag <= 1'b0 ;endendmodule

module led_paoma (input		wire				sys_clk      ,input		wire				sys_rst_n    ,output		reg     [3:0]       led_out     
);parameter   MAX_CNT_500MS = 25_000_000 ;// reg signal definereg     [24:0]      cnt_500ms ;reg     [ 1:0]      cnt_state ;// wire signal definewire                add_cnt_500ms ;wire                end_cnt_500ms ;wire                add_cnt_state ;wire                end_cnt_state ;
/******************************************************************************************
********************************************main code**************************************
*******************************************************************************************/// reg     [24:0]      cnt_500ms ;always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) cnt_500ms <= 25'd0 ;else if(add_cnt_500ms) beginif(end_cnt_500ms)cnt_500ms <= 25'd0 ;else cnt_500ms <= cnt_500ms + 1'b1 ;endelse cnt_500ms <= 25'd0 ;end// reg     [ 1:0]      cnt_state ;always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) cnt_state <= 2'd0 ;else if(add_cnt_state) beginif(end_cnt_state)cnt_state <= 2'd0 ;else cnt_state <= cnt_state + 1'b1 ;end else cnt_state <= cnt_state ;end// // wire signal define// wire                add_cnt_500ms ;assign  add_cnt_500ms = 1'b1 ;// wire                end_cnt_500ms ;assign  end_cnt_500ms = add_cnt_500ms && (cnt_500ms == (MAX_CNT_500MS - 1)) ;// wire                add_cnt_state ;assign  add_cnt_state = end_cnt_500ms ;// wire                end_cnt_state ;assign  end_cnt_state = ((add_cnt_state && (cnt_state == 2'b11 )) ) ; // output reg [3:0]     led_out always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) led_out <= 4'b0000 ;else case (cnt_state)2'b00 :     led_out <= 4'b0001 ;2'b01 :     led_out <= 4'b0010 ;2'b10 :     led_out <= 4'b0100 ;2'b11 :     led_out <= 4'b1000 ;default:    led_out <= 4'b0000 ;endcaseend
endmodule

module shanshuo (input		wire				sys_clk      ,input		wire				sys_rst_n    ,output		reg     [3:0]       led_out     
);parameter   MAX_CNT_500MS = 25_000_000 ;// reg signal definereg     [24:0]      cnt_500ms ;// wire signal definewire                add_cnt_500ms ;wire                end_cnt_500ms ;
/******************************************************************************************
********************************************main code**************************************
*******************************************************************************************/// reg     [24:0]      cnt_500ms ;always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) cnt_500ms <= 25'd0 ;else if(add_cnt_500ms) beginif(end_cnt_500ms)cnt_500ms <= 25'd0 ;else cnt_500ms <= cnt_500ms + 1'b1 ;endelse cnt_500ms <= 25'd0 ;end// // wire signal define// wire                add_cnt_500ms ;assign  add_cnt_500ms = 1'b1 ;// wire                end_cnt_500ms ;assign  end_cnt_500ms = add_cnt_500ms && (cnt_500ms == (MAX_CNT_500MS - 1)) ;// output reg [3:0]     led_out always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) led_out <= 4'b0000 ;else if(end_cnt_500ms)led_out <= ~led_out ;else led_out <=  led_out ;endendmodule

module led_water (input		wire				sys_clk      ,input		wire				sys_rst_n    ,output		reg     [3:0]       led_out     
);parameter   MAX_CNT_500MS = 25_000_000 ;// reg signal definereg     [24:0]      cnt_500ms ;reg     [ 2:0]      cnt_state ; // wire signal definewire                add_cnt_500ms ;wire                end_cnt_500ms ;wire                add_cnt_state ;wire                end_cnt_state ;
/******************************************************************************************
********************************************main code**************************************
*******************************************************************************************/// reg     [24:0]      cnt_500ms ;always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) cnt_500ms <= 25'd0 ;else if(add_cnt_500ms) beginif(end_cnt_500ms)cnt_500ms <= 25'd0 ;else cnt_500ms <= cnt_500ms + 1'b1 ;endelse cnt_500ms <= 25'd0 ;end// reg     [ 1:0]      cnt_state ;always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) cnt_state <= 2'd0 ;else if(add_cnt_state) beginif(end_cnt_state)cnt_state <= 2'd0 ;else cnt_state <= cnt_state + 1'b1 ;end else cnt_state <= cnt_state ;end// // wire signal define// wire                add_cnt_500ms ;assign  add_cnt_500ms = 1'b1 ;// wire                end_cnt_500ms ;assign  end_cnt_500ms = add_cnt_500ms && (cnt_500ms == (MAX_CNT_500MS - 1)) ;// wire                add_cnt_state ;assign  add_cnt_state = end_cnt_500ms ;// && led_flag// wire                end_cnt_state ;assign  end_cnt_state = ((add_cnt_state && (cnt_state == 3'b101 )) ) ; // output reg [3:0]     led_out always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) led_out <= 4'b0000 ;else case (cnt_state)3'b000 :     led_out <= 4'b0001 ;3'b001 :     led_out <= 4'b0010 ;3'b010 :     led_out <= 4'b0100 ;3'b011 :     led_out <= 4'b1000 ;3'b100 :     led_out <= 4'b0100 ;3'b101 :     led_out <= 4'b0010 ;default:     led_out <= 4'b0000 ;endcaseend
endmodule

module state_led_ctrl (input		wire				sys_clk         ,input		wire				sys_rst_n       ,input       wire                water_flag      ,input       wire                paoma_flag      ,input       wire                shanshuo_flag   ,input       wire    [3:0]       led_water       ,input       wire    [3:0]       led_paoma       ,input       wire    [3:0]       led_shanshuo    ,output	    reg     [3:0]       led_out         
);localparam          IDLE        = 4'b0001 ,WATER       = 4'b0010 ,PAOMA       = 4'b0100 ,SHANSHUO    = 4'b1000 ;// reg signal definereg     [3:0]       state_c ;reg     [3:0]       state_n ;// wire signalwire                IDLEtoWATER         ;wire                IDLEtoPAOMA         ;wire                IDLEtoSHANSHUO      ;wire                WATERtoPAOMA        ;wire                WATERtoSHANSHUO     ;wire                PAOMAtoWATER        ;wire                PAOMAtoSHANSHUO     ;wire                SHANSHUOtoPAOMA     ;wire                SHANSHUOtoWATER     ;
/******************************************************************************************
********************************************main code**************************************
*******************************************************************************************/// // reg signal define// reg         state_c ;always @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) state_c <= IDLE ;elsestate_c <= state_n ;end// reg         state_n ;always @(*) begincase(state_c)IDLE     :  if(IDLEtoWATER)state_n = WATER ;else if(IDLEtoPAOMA)state_n = PAOMA ;else if(IDLEtoSHANSHUO)state_n = SHANSHUO ;else state_n = IDLE ;WATER    :  if(WATERtoPAOMA)state_n = PAOMA ;else if(WATERtoSHANSHUO)state_n = SHANSHUO ;else state_n = WATER ;PAOMA    :  if(PAOMAtoWATER)state_n = WATER ;else if(PAOMAtoSHANSHUO)state_n = SHANSHUO ;else state_n = PAOMA ;SHANSHUO :  if(SHANSHUOtoPAOMA)state_n = PAOMA ;else if(SHANSHUOtoWATER)state_n = WATER ;else state_n = SHANSHUO ;default  :  state_n = IDLE ;endcaseendassign  IDLEtoWATER         = (state_c == IDLE      ) && (water_flag   ) ;assign  IDLEtoPAOMA         = (state_c == IDLE      ) && (paoma_flag   ) ;assign  IDLEtoSHANSHUO      = (state_c == IDLE      ) && (shanshuo_flag) ;assign  WATERtoPAOMA        = (state_c == WATER     ) && (paoma_flag   ) ;assign  WATERtoSHANSHUO     = (state_c == WATER     ) && (shanshuo_flag) ;assign  PAOMAtoWATER        = (state_c == PAOMA     ) && (water_flag   ) ;assign  PAOMAtoSHANSHUO     = (state_c == PAOMA     ) && (shanshuo_flag) ;assign  SHANSHUOtoPAOMA     = (state_c == SHANSHUO  ) && (paoma_flag   ) ;assign  SHANSHUOtoWATER     = (state_c == SHANSHUO  ) && (water_flag   ) ;// led_outalways @(posedge sys_clk or negedge sys_rst_n) beginif(~sys_rst_n) led_out <= 4'hf ;else case (state_c)IDLE    :   led_out <= 4'hf ;WATER   :   led_out <= led_water    ;PAOMA   :   led_out <= led_paoma    ;SHANSHUO:   led_out <= led_shanshuo ;default:    led_out <= 4'hf ;endcaseendendmodule

module top (input		wire				sys_clk         ,input		wire				sys_rst_n       ,input       wire                key_water       ,input       wire                key_paoma       ,input       wire                key_shanshuo    ,output		wire    [3:0]       led_out         
);// inst wirewire                water_flag      ;wire                paoma_flag      ;wire                shanshuo_flag   ;wire    [3:0]       led_water       ;wire    [3:0]       led_paoma       ;wire    [3:0]       led_shanshuo    ;// inst
key_filter key_filter_inst_water(.sys_clk                ( sys_clk       ) ,.sys_rst_n              ( sys_rst_n     ) ,.key_in                 ( key_water     ) ,.key_flag               ( water_flag    )  
);key_filter key_filter_inst_paoma(.sys_clk                ( sys_clk       ) ,.sys_rst_n              ( sys_rst_n     ) ,.key_in                 ( key_paoma     ) ,.key_flag               ( paoma_flag    )  
);key_filter key_filter_inst_shanshuo(.sys_clk                ( sys_clk       ) ,.sys_rst_n              ( sys_rst_n     ) ,.key_in                 ( key_shanshuo  ) ,.key_flag               ( shanshuo_flag )  
);led_water led_water_isnt (.sys_clk                ( sys_clk       ) ,.sys_rst_n              ( sys_rst_n     ) ,.led_out                ( led_water     )  
);led_paoma led_paoma_inst(.sys_clk                ( sys_clk       ) ,.sys_rst_n              ( sys_rst_n     ) ,.led_out                ( led_paoma     )  
);shanshuo shanshuo_inst(.sys_clk                ( sys_clk       ) ,.sys_rst_n              ( sys_rst_n     ) ,.led_out                ( led_shanshuo  )  
);state_led_ctrl state_led_ctrl_inst(.sys_clk                ( sys_clk       ) ,.sys_rst_n              ( sys_rst_n     ) ,.water_flag             ( water_flag    ) ,.paoma_flag             ( paoma_flag    ) ,.shanshuo_flag          ( shanshuo_flag ) ,.led_water              ( led_water     ) ,.led_paoma              ( led_paoma     ) ,.led_shanshuo           ( led_shanshuo  ) ,.led_out                ( led_out       )  
);endmodule

仿真：

`timescale 1ns/1ns
module test_top ();reg 				sys_clk         ;reg 				sys_rst_n       ;reg                 key_water       ;reg                 key_paoma       ;reg                 key_shanshuo    ;wire    [3:0]       led_out         ;top top_inst(.sys_clk            ( sys_clk       ) ,.sys_rst_n          ( sys_rst_n     ) ,.key_water          ( key_water     ) ,.key_paoma          ( key_paoma     ) ,.key_shanshuo       ( key_shanshuo  ) ,.led_out            ( led_out       )  
);defparam    top_inst.key_filter_inst_water.MAX_CNT_10MS     = 50 ;defparam    top_inst.key_filter_inst_paoma.MAX_CNT_10MS     = 50 ;defparam    top_inst.key_filter_inst_shanshuo.MAX_CNT_10MS  = 50 ;defparam    top_inst.led_water_isnt.MAX_CNT_500MS           = 50 ;defparam    top_inst.led_paoma_inst.MAX_CNT_500MS           = 50 ;defparam    top_inst.shanshuo_inst.MAX_CNT_500MS            = 50 ;parameter   CYCLE = 20 ;initial beginsys_clk      = 1'b1 ;sys_rst_n   <= 1'b1 ;key_water   <= 1'b1 ;key_paoma   <= 1'b1 ;key_shanshuo<= 1'b1 ;#( CYCLE * 10 )     ;sys_rst_n <= 1'b0   ;#( 200 )            ;sys_rst_n <= 1'b1   ;#( CYCLE * 10 )     ;key_water <= 1'b0   ;#( CYCLE * 100 )    ;key_water <= 1'b1   ;#( CYCLE * 1000 )   ;key_paoma <= 1'b0   ;#( CYCLE * 100 )    ;key_paoma <= 1'b1   ;#( CYCLE * 1000 )   ;key_shanshuo <= 1'b0;#( CYCLE * 100 )    ;key_shanshuo <= 1'b1;#( CYCLE * 1000 )   ;$stop               ;endalways #( CYCLE / 2 ) sys_clk = ~sys_clk ;endmodule