防抖设计

led_matrix/tb_lm_2.v

@@ -2,6 +2,7 @@
 
 module tb_lm();
 
+
 reg k_1;  // 显示的图像1
 reg k_2;  // 显示的图像2
 
@@ -10,13 +11,17 @@ reg key;  // 物理按键 开关显示, 该按键异步的, 每次按下 等于
 reg key_1;  // 物理按键的随时钟同步变化信号
 reg key_2;  // 
 reg is_show;  // 互斥变化的
+reg [4:0] flag_time;
 
-reg flag;  // 状态改变周期 现在500ns改变一次状态, 显示相反的图像
+reg flag;  // 状态改变周期 现在500纳秒改变一次状态, 显示相反的图像
 
 reg sys_clk;
 reg sys_rst;
 
 
+reg [7:0]x;
+reg [7:0]y;
+
 always #10 sys_clk = ~sys_clk;
 
 initial begin
@@ -28,11 +33,21 @@ initial begin
     // 延迟2000纳秒, 现在x 应该是0
     #2000
 
-    // 按下一次key, 持续188纳秒
+
     key <= 1'b1;
-    #188
+    #120
     key <= 1'b0;
-    #400
+    #20
+
+    key <= 1'b1;
+    #80
+    key <= 1'b0;
+    #20
+
+    key <= 1'b1;
+    #90
+    key <= 1'b0;
+    #20
 
     // 延迟4000纳秒观察
     {k_2, k_1} <= 2'b10;
@@ -40,29 +55,53 @@ initial begin
     {k_2, k_1} <= 2'b01;
     #3800
 
-    // 按下一次key, 持续288纳秒, 现在应该是关闭显示了, x为0
+
+    key <= 1'b1;
+    #20
+    key <= 1'b0;
+    #20
+
     key <= 1'b1;
-    #288
+    #20
     key <= 1'b0;
+    #20
+
+    key <= 1'b1;
+    #90
+    key <= 1'b0;
+    #200
+
+    key <= 1'b1;
+    #120
+    key <= 1'b0;
+    #20
+
+    key <= 1'b1;
+    #120
+    key <= 1'b0;
+    #20
+
+    key <= 1'b1;
+    #150
+    key <= 1'b0;
+
 end
 
 
-reg [5:0] CNT;
+// 显示的时候计时
 always @(posedge sys_clk or negedge sys_rst) begin
     if (sys_rst == 1'b0) begin
-        CNT <= 5'd0;
+        flag_time <= 5'd0;
     end
-    else if (CNT < (5'd25 - 5'd1)) begin
-        CNT <= CNT + 5'd1;
+    else if (flag_time < (5'd25 - 5'd1) && is_show) begin
+        flag_time <= flag_time + 5'd1;
     end
     else begin
-        CNT <= 5'b0;
+        flag_time <= 5'b0;
     end
 end
 
 
-reg [7:0]x;
-reg [7:0]y;
 always @(posedge sys_clk or negedge sys_rst) begin
     if (sys_rst == 1'b0) begin
         {k_2, k_1} <= 2'b11;
@@ -86,11 +125,12 @@ always @(posedge sys_clk or negedge sys_rst) begin
     end
 end
 
+// 每 显示500ns 改变显示的图像
 always @(posedge sys_clk or negedge sys_rst) begin
     if (sys_rst == 1'b0) begin
         flag <= 1'b0;
     end
-    else if (CNT == (5'd25 - 5'd1)) begin
+    else if (flag_time == (5'd25 - 5'd1)) begin
         flag <= !flag;
     end
     else begin
@@ -112,13 +152,47 @@ end
 
 // 用一个时钟周期即可判断是否在当前时钟周期上升沿之前, 按下了按键
 assign is_click = key_1 && !key_2;
+
+// 消抖, 在20个时钟周期内, 持续10个周期高电平, 即 按下了
+reg [4:0] down_time;  // max: 10
+reg [4:0] click_time;  // max: 20
+reg is_lock = 1'b0;  // 
+
 // 使用时钟约束一下
 always @(posedge sys_clk or negedge sys_rst) begin
     if (sys_rst == 1'b0) begin
         is_show <= 1'b0;
+        down_time <= 5'd0;
+        click_time <= 5'd0;
     end
+    // 只要按下就上锁
     else if (is_click) begin
-        is_show <= !is_show;
+        is_lock <= 1'b1;
+    end 
+    else begin
+    end
+
+    // 锁定的时间到了, 解锁, 然后判断并重置
+    if (is_lock && click_time == 5'd20 - 5'd1) begin
+        is_lock <= 1'b0;
+        click_time <= 5'd0;
+        down_time <= 5'd0;
+        // 判断按下的持续时间
+        if (down_time > 5'd10 - 5'd1) begin
+            is_show <= !is_show;
+        end
+        else begin
+        end
+    end
+    // 上锁了但是时间没到
+    else if (is_lock && click_time < 5'd20 - 5'd1) begin
+        click_time <= click_time + 5'd1;
+        // 如果还按着
+        if (key_1) begin
+            down_time <= down_time + 1'd1;
+        end
+        else begin
+        end
     end
     else begin
     end

led_matrix/tb_lm_2.v.out

@@ -0,0 +1,75 @@
+#! /usr/local/Cellar/icarus-verilog/12.0/bin/vvp
+:ivl_version "12.0 (stable)";
+:ivl_delay_selection "TYPICAL";
+:vpi_time_precision - 9;
+:vpi_module "/usr/local/Cellar/icarus-verilog/12.0/lib/ivl/system.vpi";
+:vpi_module "/usr/local/Cellar/icarus-verilog/12.0/lib/ivl/vhdl_sys.vpi";
+:vpi_module "/usr/local/Cellar/icarus-verilog/12.0/lib/ivl/vhdl_textio.vpi";
+:vpi_module "/usr/local/Cellar/icarus-verilog/12.0/lib/ivl/v2005_math.vpi";
+:vpi_module "/usr/local/Cellar/icarus-verilog/12.0/lib/ivl/va_math.vpi";
+S_0x7f94c3905560 .scope module, "tb_lm" "tb_lm" 2 3;
+ .timescale -9 -9;
+v0x7f94c390a240_0 .var "k_1", 0 0;
+v0x7f94c3919630_0 .var "k_2", 0 0;
+v0x7f94c39196d0_0 .var "key", 0 0;
+v0x7f94c3919760_0 .var "sys_clk", 0 0;
+v0x7f94c3919800_0 .var "sys_rst", 0 0;
+    .scope S_0x7f94c3905560;
+T_0 ;
+    %delay 10, 0;
+    %load/vec4 v0x7f94c3919760_0;
+    %inv;
+    %store/vec4 v0x7f94c3919760_0, 0, 1;
+    %jmp T_0;
+    .thread T_0;
+    .scope S_0x7f94c3905560;
+T_1 ;
+    %pushi/vec4 0, 0, 1;
+    %assign/vec4 v0x7f94c3919760_0, 0;
+    %pushi/vec4 0, 0, 1;
+    %assign/vec4 v0x7f94c3919800_0, 0;
+    %delay 200, 0;
+    %pushi/vec4 1, 0, 1;
+    %assign/vec4 v0x7f94c3919800_0, 0;
+    %delay 2000, 0;
+    %pushi/vec4 1, 0, 1;
+    %assign/vec4 v0x7f94c39196d0_0, 0;
+    %delay 2, 0;
+    %pushi/vec4 0, 0, 1;
+    %assign/vec4 v0x7f94c39196d0_0, 0;
+    %delay 2, 0;
+    %pushi/vec4 1, 0, 1;
+    %assign/vec4 v0x7f94c39196d0_0, 0;
+    %delay 2, 0;
+    %pushi/vec4 0, 0, 1;
+    %assign/vec4 v0x7f94c39196d0_0, 0;
+    %delay 2, 0;
+    %pushi/vec4 1, 0, 1;
+    %assign/vec4 v0x7f94c39196d0_0, 0;
+    %delay 2, 0;
+    %pushi/vec4 0, 0, 1;
+    %assign/vec4 v0x7f94c39196d0_0, 0;
+    %delay 2, 0;
+    %pushi/vec4 2, 0, 2;
+    %split/vec4 1;
+    %assign/vec4 v0x7f94c390a240_0, 0;
+    %assign/vec4 v0x7f94c3919630_0, 0;
+    %delay 3900, 0;
+    %pushi/vec4 1, 0, 2;
+    %split/vec4 1;
+    %assign/vec4 v0x7f94c390a240_0, 0;
+    %assign/vec4 v0x7f94c3919630_0, 0;
+    %delay 3800, 0;
+    %pushi/vec4 1, 0, 1;
+    %assign/vec4 v0x7f94c39196d0_0, 0;
+    %delay 2, 0;
+    %pushi/vec4 0, 0, 1;
+    %assign/vec4 v0x7f94c39196d0_0, 0;
+    %delay 2, 0;
+    %end;
+    .thread T_1;
+# The file index is used to find the file name in the following table.
+:file_names 3;
+    "N/A";
+    "<interactive>";
+    "tb_lm_2.v";