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--- pulse_gen [2021/09/13 10:58]
gongyu 创建
+++ pulse_gen [2021/09/13 22:49] (当前版本)
gongyu
@@ 行 7: / 行 7: @@
 ### 2. 设计要求
-  - 掌握Verilog子模块的调用
+  - 掌握[[Verilog]]子模块的调用
-  - 掌握PWM和脉冲发生的原理
+  - 掌握[[PWM]]和脉冲发生的原理
   - 基于[[STEP-Baseboard]]平台实现脉冲发生器的设计，周期可调，占空比可调
@@ 行 151: / 行 151: @@
-====参考文档====
+### 9. 参考文档
   * [[按键消抖]]
   * {{:machxo2familydatasheet.pdf|Lattice MachXO2数据手册}}
+### 10. 相关代码
+#### 10.1 脉冲发生器代码
+可下载文件：[[Pulse_gen.v|脉冲发生器Top文件]]
+<code verilog>
+// --------------------------------------------------------------------
+// >>>>>>>>>>>>>>>>>>>>>>>>> COPYRIGHT NOTICE <<<<<<<<<<<<<<<<<<<<<<<<<
+// --------------------------------------------------------------------
+// Module: Pulse_gen
+//
+// Author: Step
+//
+// Description: Pulse generate module
+//
+// Web: www.ecbcamp.com
+//
+// --------------------------------------------------------------------
+// Code Revision History :
+// --------------------------------------------------------------------
+// Version: |Mod. Date:   |Changes Made:
+// V1.0     |2015/11/11   |Initial ver
+// --------------------------------------------------------------------
+module Pulse_gen
+(
+input					clk_in,
+input					rst_n_in,
+input					key_menu,
+input					key_up,
+input					key_down,
+output					menu_state,
+output	reg				pulse_out
+);
-====相关文档====
+//Debounce for key
+wire [2:0] key_state,key_pulse;
+Debounce1 Debounce_uut
+(
+.clk(clk_in),
+.rst_n(rst_n_in),
+.key_n({key_menu,key_up,key_down}),
+.key_state(key_state),
+.key_pulse(key_pulse)
+);
-^ **文件名称**  | **功能** |
+wire menu_state = key_state[2];
-^ **[[Pulse_gen.v]]** | **脉冲发生器TOP文件** |
+wire up_pulse = key_pulse[1];
-^ **[[Debounce1.v]]** | **按键消抖** |
+wire down_pulse = key_pulse[0];
+reg	[3:0] cycle;
+reg	[3:0] duty;
+//Control cycle and duty cycle
+always @(posedge clk_in or negedge rst_n_in) begin
+	if(!rst_n_in) begin
+		cycle<=4'd8;
+		duty<=4'd4;
+	end else begin
+		if(menu_state) begin
+			if(up_pulse && (cycle<4'd15)) cycle <= cycle + 4'd1;
+			else if(down_pulse && (cycle>(duty+4'd1))) cycle <= cycle - 4'd1;
+			else cycle <= cycle;
+		end else begin
+			if(up_pulse && (cycle>(duty+4'd1))) duty <= duty + 4'd1;
+			else if(down_pulse && (duty>4'd0)) duty <= duty - 4'd1;
+			else duty <= duty;
+		end
+	end
+end
+reg	[3:0]	cnt;
+//counter for cycle
+always @(posedge clk_in or negedge rst_n_in) begin
+	if(!rst_n_in) begin
+		cnt<=4'd0;
+	end else begin
+		if(cnt>=cycle) cnt<=4'd0;
+		else cnt <= cnt + 4'd1;
+	end
+end
+//pulse generate with duty
+always @(posedge clk_in or negedge rst_n_in) begin
+	if(!rst_n_in) begin
+		pulse_out<=1'b1;
+	end else begin
+		if(cnt<=duty) pulse_out<=1'b1;
+		else pulse_out<=1'b0;
+	end
+end
+endmodule
+</code>
+#### 10.2 按键消抖部分的代码
+可下载代码：[[Debounce1.v|按键消抖设计代码]]
+<code verilog>
+// --------------------------------------------------------------------
+// >>>>>>>>>>>>>>>>>>>>>>>>> COPYRIGHT NOTICE <<<<<<<<<<<<<<<<<<<<<<<<<
+// --------------------------------------------------------------------
+// Module: Debounce1
+//
+// Author: Step
+//
+// Description: Debounce for button with FPGA/CPLD
+//
+// Web: www.ecbcamp.com
+//
+// --------------------------------------------------------------------
+// Code Revision History :
+// --------------------------------------------------------------------
+// Version: |Mod. Date:   |Changes Made:
+// V1.0     |2015/11/11   |Initial ver
+// --------------------------------------------------------------------
+module Debounce1(clk,rst_n,key_n,key_pulse,key_state);
+input   				clk;			//system clock
+input   				rst_n;			//system reset
+input   		[2:0]	key_n;			//button input
+output  		[2:0]	key_pulse;		//Debounce pulse output
+output	reg		[2:0]	key_state;		//Debounce state output
+reg [2:0] key_rst;
+//Register key_rst, lock key_n to next clk
+always @(posedge clk  or  negedge rst_n)
+    if (!rst_n) key_rst <= 3'b111;
+    else  key_rst <=key_n;
+//Detect the edge of key_n
+wire  key_an = (key_rst==key_n)? 0:1;
+reg[18:0]  cnt;
+//Count the number of clk when a edge of key_n is occured
+always @ (posedge clk  or negedge rst_n)
+    if (!rst_n) cnt <= 19'd0;
+    else if(key_an) cnt <=19'd0;
+    else cnt <= cnt + 1'b1;
+reg [2:0] low_sw;
+//Lock the status to register low_sw when cnt count to 19'd500000
+always @(posedge clk  or  negedge rst_n)
+    if (!rst_n)  low_sw <= 3'b111;
+	else if (cnt == 19'd500000)
+        low_sw <= key_n;
+reg [2:0] low_sw_r;
+//Register low_sw_r, lock low_sw to next clk
+always @ ( posedge clk  or  negedge rst_n )
+    if (!rst_n) low_sw_r <= 3'b111;
+    else  low_sw_r <= low_sw;
+wire [2:0] key_pulse;
+//Detect the negedge of low_sw, generate pulse
+assign key_pulse= low_sw_r & ( ~low_sw);
+//Detect the negedge of low_sw, generate state
+always @(posedge clk or negedge rst_n)
+	if (!rst_n) key_state <= 3'b111;
+	else if(key_pulse[0]) key_state[0] <= ~key_state[0];
+	else if(key_pulse[1]) key_state[1] <= ~key_state[1];
+	else if(key_pulse[2]) key_state[2] <= ~key_state[2];
+	else key_state <= key_state;
+endmodule
+</code>