差别

这里会显示出您选择的修订版和当前版本之间的差别。

到此差别页面的链接

@@ 行 1: / 行 1: @@
+====呼吸灯设计文件====
+<code verilog>
+// --------------------------------------------------------------------
+// >>>>>>>>>>>>>>>>>>>>>>>>> COPYRIGHT NOTICE <<<<<<<<<<<<<<<<<<<<<<<<<
+// --------------------------------------------------------------------
+// Module: Breath_led
+//
+// Author: Step
+//
+// Description: PWM-Breath_led
+//
+// Web: www.ecbcamp.com
+//
+// --------------------------------------------------------------------
+// Code Revision History :
+// --------------------------------------------------------------------
+// Version: |Mod. Date:   |Changes Made:
+// V1.0     |2015/11/11   |Initial ver
+// --------------------------------------------------------------------
+module Breath_led #
+(
+parameter	CNT_NUM = 5000	//period = (5000^2)*2 = 50000000 = 2s
+)
+(
+input		clk_in,			//system clk
+input		rst_n_in,			//system reset
+output		Breath_led		//Breath led output
+);
+reg	[12:0]	cnt1;
+//generate cnt1 signal
+always@(posedge clk_in or negedge rst_n_in) begin
+	if(!rst_n_in) begin
+		cnt1<=13'd0;
+	end else begin
+		if(cnt1>=CNT_NUM-1) cnt1<=1'b0;
+		else cnt1<=cnt1+1'b1;
+	end
+end
+reg	flag;
+reg	[12:0]	cnt2;
+//generate cnt2 signal
+always@(posedge clk_in or negedge rst_n_in) begin
+	if(!rst_n_in) begin
+		cnt2<=13'd0;
+		flag<=1'b0;
+	end else begin
+		if(cnt1==CNT_NUM-1) begin
+			if(!flag) begin
+				if(cnt2>=CNT_NUM-1) flag<=1'b1;
+				else cnt2<=cnt2+1'b1;
+			end else begin
+				if(cnt2<=0) flag<=1'b0;
+				else cnt2<=cnt2-1'b1;
+			end
+		end else cnt2<=cnt2;
+	end
+end
+//Compare cnt1 and cnt2, generate PWM-Breath-led
+assign	Breath_led = (cnt1<cnt2)?1'b0:1'b1;
+endmodule
+</code>