顶层模块：mix_module
module mix_module
(
CLK, RSTn, Flash_LED, Run_LED
);
input CLK;
input RSTn;
output Flash_LED;
output [2:0]Run_LED;
/**********************************/
//wire Flash_LED;
//reg Flash_LED;
flash_module U1
(
.CLK( CLK ),
.RSTn( RSTn ),
.LED_Out( Flash_LED )
);
/**********************************/
//wire [2:0]Run_LED;
//reg [2:0]Run_LED;
run_module U2
(
.CLK( CLK ),
.RSTn( RSTn ),
.LED_Out( Run_LED )
);
/***********************************/
//assign Flash_LED = Flash_LED;
// assign Run_LED = Run_LED;
/**********************************/
endmodule
子模块1：flash_module
module flash_module
(
CLK, RSTn, LED_Out
);
input CLK;
input RSTn;
output reg LED_Out;
/*********************************/
parameter T50MS = 22'd2_499_999;//DB4CE15使用的晶振为50MHz，50M*0.05-1=2_499_999
/********************************/
reg [21:0]Count1;
always @ ( posedge CLK or negedge RSTn )
if( !RSTn )
Count1 <= 22'd0;
else if( Count1 == T50MS )
Count1 <= 22'd0;
else
Count1 <= Count1 + 1'b1;
/*********************************/
//reg rLED_Out;
always @ ( posedge CLK or negedge RSTn )
if( !RSTn )
LED_Out <= 1'b0;
else if( Count1 == T50MS )
LED_Out <= ~LED_Out;
/*********************************/
//assign LED_Out = rLED_Out;
endmodule
子模块2：run_module
module run_module
(
CLK, RSTn, LED_Out
);
input CLK;
input RSTn;
output [2:0]LED_Out;
/**************************/
parameter T1MS = 16'd49_999;//DB4CE15使用的晶振为50MHz，50M*0.001-1=49_999
/**************************/
reg [15:0]Count1;
always @ ( posedge CLK or negedge RSTn )//1ms计数器
if( !RSTn )
Count1 <= 16'd0;
else if( Count1 == T1MS )
Count1 <= 16'd0;
else
Count1 <= Count1 + 1'b1;
/*****************************************/
reg [9:0]Count_MS;
always @ ( posedge CLK or negedge RSTn )//100ms计数器
if( !RSTn )
Count_MS <= 10'd0;
else if( Count_MS == 10'd100 )
Count_MS <= 10'd0;
else if( Count1 == T1MS )
Count_MS <= Count_MS + 1'b1;
/*********************************/
reg [2:0]rLED_Out;
always @ ( posedge CLK or negedge RSTn )
if( !RSTn )
rLED_Out <= 3'b001;
else if( Count_MS == 10'd100 )
begin
if( rLED_Out == 3'b000 )
rLED_Out <= 3'b001;
else
rLED_Out <= { rLED_Out[1:0], 1'b0 };//向左移位1bit操作
end
/*****************************/
assign LED_Out = rLED_Out;
/*****************************/
endmodule