flicker_led.v

采用Altera公司的CycloneII芯片EP2C8的一些程序代码。

module Flicker_Led(
						Clk,						
						Rst_n,
							
						Led_En_n,				
						Led,
						
						Buzz,
						Sev_Seg_Led_Sel_n
					);

input Clk;		//定义输入时钟
input Rst_n;		//定义复位输入

output Led_En_n;
output [7:0] Led;	//定义输出端口

output Buzz;
output [3:0] Sev_Seg_Led_Sel_n;

/*---------------------------------------------------*/
reg [31:0] Cout;	//时钟计数

	always @(posedge Clk or negedge Rst_n)
		begin
			if(~Rst_n)
				begin
					Cout <= 32'd0;
				end
			else
				begin
					//计至0.5s清零
					Cout <= (Cout == 32'd25_000_000) ? 32'd0 : (Cout + 32'd1);
				end
		end
/*---------------------------------------------------*/
reg Clk_En;

	always @(posedge Clk or negedge Rst_n)
		begin
			if(~Rst_n)
				begin
					Clk_En <= 1'd0;
				end
			else
				begin
					//每0.5s产生一个时钟使能
					Clk_En <= (Cout == 32'd25_000_000) ? 1'd1 : 1'd0;
				end
		end
/*---------------------------------------------------*/
	assign 
		Led_En_n = 1'd0;  //led使能，低有效	
		
reg [7:0] Led;

	always @(posedge Clk or negedge Rst_n)
		begin
			if(~Rst_n)
				begin
					Led <= 8'd0;
				end
			else
				//每来一个使能，LED变化一次
				if(Clk_En)
					begin
						Led <= ~Led;
					end
		end	
/*---------------------------------------------------*/
	assign
		Buzz = 1'd0;  //禁止蜂鸣器工作
		
	assign
		Sev_Seg_Led_Sel_n = 4'b1111;  //禁止七段数码管显示
/*---------------------------------------------------*/

endmodule