[Verilog] 薄膜建盤4X4 電路程式設計

最近研究需要用到4X4薄膜鍵盤設計。
就稍微研究了一下，有些資料參考這網站介紹還蠻清楚的。
原理就是，行1~行4送掃描碼，列1~列4讀值。
例如:
1. 行1~行4送 (0111)2進制的值，如果列1~列4讀到(0111)就表示Key 1被按下了。
2. 行1~行4送 (1101)2進制的值，如果列1~列4讀到(1011)就表示Key 6被按下了。
所以Verilog在寫程式的時候就要看現在是送那一列的掃描碼，讀進來後是哪一個為0代表被按下。
[Note] 其中每個列的訊號端需要接一個pull high電組，以防止腳位浮接。
程式碼如下:
  1 // --------------------------------------------------------------------
  2 // Copyright (c) 2011 by TKU ICLAB. 
  3 // --------------------------------------------------------------------
  4 /*  use follow instruction to call the function
  5 
  6                             4X4 Keypad
  7            Pin1    Pin2    Pin3    Pin4    Pin5    Pin6    Pin7    Pin8
  8 function   row1    row2    row3    row4    col1    col2    col3    col4
  9 
 10 FPGA PIN  iKey_Read[3]  ~  iKey_Read[0] | oKey_Scan[3]  ~  oKey_Scan[0]
 11 
 12  */
 13 `define default_netype none 
 14 module Keypad4X4_top (
 15         iClk_50M,       // 50Mhz
 16         iRst_n,     // reset_n
 17         
 18         iKey_Read,  // Key Read 
 19         oKey_Scan,  // Key Scan code
 20         
 21         oDval,      // a trigger
 22         oKeyCode,    //  Key code4
 23         oKey
 24 
 25     );
 26 //===========================================================================
 27 // PORT declarations
 28 //===========================================================================
 29 input           iClk_50M;
 30 input           iRst_n;
 31         
 32 input   [3:0]   iKey_Read;  // Key Read 
 33 output  [3:0]   oKey_Scan;  // Key Scan code
 34         
 35 output          oDval;      // a trigger
 36 output  [4:0]   oKeyCode;   // Key code
 37 output  [15:0]  oKey;
 38 //=============================================================================
 39 // REG/WIRE declarations
 40 //=============================================================================
 41 reg  [15:0]  oKey;
 42 reg             oDval, rDval;
 43 reg     [3:0]   oKey_Scan;
 44 reg     [4:0]   oKeyCode;
 45 wire            wClk_1khz;
 46 wire    [2:0]   wKey_Dly;
 47 reg     [1:0]   rCnt, rSt;
 48 reg     [4:0]   rKeyCode, rKeyCode_d1, rKeyCode_d2, rKeyCode_d3;
 49 reg     [3:0]   rKey_Read_Dly0, rKey_Read_Dly1;
 50 reg     [3:0]   rKey_Read;
 51 wire            wclk4X;
 52 reg             rPressKey;
 53 //=============================================================================
 54 // Structural coding
 55 //=============================================================================
 56 ///*
 57 Clkdiv #( .CLKFREQ(50000000), .EXCEPTCLK(500000), .multipleX(4) ) UX1
 58         (   
 59             .iClk50M(iClk_50M),  // 50Mhz clock 
 60             .iRst_n(iRst_n),
 61             .oClk(wClk_1khz),     // 1ms clock
 62             .oSampClk(wclk4X),  // multipleX expect clock, for SignalTap use
 63         );
 64 //*/
 65 
 66 //// send column scan 
 67 always@(posedge wClk_1khz or negedge iRst_n) begin
 68     if(!iRst_n) begin
 69         rCnt <= 0;
 70         oKey_Scan <= 0;
 71         rSt <= 0;
 72     end
 73     else begin
 74         case(rSt)
 75             2'b00:  begin   oKey_Scan <= 4'b0111; rCnt <= rCnt+2'b1;
 76                             if(rCnt == 3)  rSt <= rSt + 1;
 77                             else rSt <= rSt; end // 1 column
 78             2'b01:  begin   oKey_Scan <= 4'b1011; rCnt <= rCnt+2'b1; 
 79                             if(rCnt == 3)  rSt <= rSt + 1;
 80                             else rSt <= rSt;
 81                                               end // 2 column
 82             2'b10:  begin   oKey_Scan <= 4'b1101; rCnt <= rCnt+2'b1; 
 83                             if(rCnt == 3)  rSt <= rSt + 1;
 84                             else rSt <= rSt;   end // 3 column
 85             default:  begin   oKey_Scan <= 4'b1110; rCnt <= rCnt+2'b1; 
 86                             if(rCnt == 3)  rSt <= rSt + 1;
 87                             else rSt <= rSt;  end // 4 column
 88         endcase
 89     end
 90 end
 91 
 92 // send column scan 
 93 always@(posedge wClk_1khz or negedge iRst_n) begin
 94     if(!iRst_n) begin
 95         oKey <= 0;
 96         rDval <= 0;
 97         rKeyCode <= 0;
 98         rPressKey <= 0;
 99     end
100     else begin
101         oKey <= oKey;
102         //  read row
103         case(iKey_Read)
104             4'b0111:  begin     // 1 row
105                     oKey[3:0] <= 0;
106                     case(oKey_Scan)
107                         4'b0111: begin rDval <= 1; rKeyCode <= 5'd1;  oKey[0] <= 1; end//'1'
108                         4'b1011: begin rDval <= 1; rKeyCode <= 5'd2;  oKey[1] <= 1; end//'2'
109                         4'b1101: begin rDval <= 1; rKeyCode <= 5'd3;  oKey[2] <= 1; end//'3'
110                         4'b1110: begin rDval <= 1; rKeyCode <= 5'd10; oKey[3] <= 1; end//'A'
111                         default: begin rDval <= 0; rKeyCode <= 5'd16; oKey[3:0] <= 0;end//'E'
112                     endcase
113                       end 
114             4'b1011:  begin     // 2 row
115                     oKey[7:4] <= 0;
116                     case(oKey_Scan)
117                         4'b0111: begin rDval <= 1; rKeyCode <= 5'd4;  oKey[4] <= 1;end//'4'
118                         4'b1011: begin rDval <= 1; rKeyCode <= 5'd5;  oKey[5] <= 1;end//'5'
119                         4'b1101: begin rDval <= 1; rKeyCode <= 5'd6;  oKey[6] <= 1;end//'6'
120                         4'b1110: begin rDval <= 1; rKeyCode <= 5'd11; oKey[7] <= 1;end //'B'
121                         default: begin rDval <= 0; rKeyCode <= 5'd16; oKey[7:4] <= 0;end //'E'
122                     endcase
123                       end 
124             4'b1101:  begin     // 3 row
125                     oKey[11:8] <= 0;
126                     case(oKey_Scan)
127                         4'b0111: begin rDval <= 1; rKeyCode <= 5'd7;  oKey[8] <= 1;end//'7'
128                         4'b1011: begin rDval <= 1; rKeyCode <= 5'd8;  oKey[9] <= 1;end//'8'
129                         4'b1101: begin rDval <= 1; rKeyCode <= 5'd9;  oKey[10] <= 1;end//'9'
130                         4'b1110: begin rDval <= 1; rKeyCode <= 5'd12; oKey[11] <= 1;end//'C'
131                         default: begin rDval <= 0; rKeyCode <= 5'd16; oKey[11:8] <= 0;end //'E'
132                     endcase
133                       end 
134             4'b1110:  begin     // 4 row
135                     oKey[15:12] <= 0;
136                     case(oKey_Scan)
137                         4'b0111: begin rDval <= 1;rKeyCode <= 5'd14;  oKey[12] <= 1; end//'*'
138                         4'b1011: begin rDval <= 1;rKeyCode <= 5'd0;   oKey[13] <= 1;end//'0'
139                         4'b1101: begin rDval <= 1;rKeyCode <= 5'd15;  oKey[14] <= 1;end//'#'
140                         4'b1110: begin rDval <= 1;rKeyCode <= 5'd13;  oKey[15] <= 1;end//'D'
141                         default: begin rDval <= 0;rKeyCode <= 5'd16;  oKey[15:12] <= 0;end//'E'
142                     endcase
143                       end
144             4'b1111:  begin     // 4 row
145                         rDval <= 0; rKeyCode <= 5'd16;   oKey <= oKey;
146                         case(oKey_Scan)
147                         4'b0111: begin rDval <= 1; rKeyCode <= 5'd1;  oKey[0] <= 0; 
148                                        oKey[4] <= 0;oKey[8] <= 0;oKey[12] <= 0;end//'1'
149                         4'b1011: begin rDval <= 1; rKeyCode <= 5'd2;  oKey[1] <= 0; 
150                                        oKey[5] <= 0;oKey[9] <= 0;oKey[13] <= 0;end//'1'end//'2'
151                         
152                         4'b1101: begin rDval <= 1; rKeyCode <= 5'd3;  oKey[2] <= 0; 
153                                        oKey[6] <= 0;oKey[10] <= 0;oKey[14] <= 0;end//'1'end//'3'
154                         4'b1110: begin rDval <= 1; rKeyCode <= 5'd10; oKey[3] <= 0; 
155                                        oKey[7] <= 0;oKey[11] <= 0;oKey[15] <= 0;end//'1'end//'A'
156                         default: begin rDval <= 0; rKeyCode <= 5'd16; oKey <= oKey;end//'E'
157                         endcase
158  
159 
160                       end 
161             default:  begin
162                       rDval <= 0; rKeyCode <= 5'd16;  
163                       oKey <= oKey;// No key press
164                       end
165         endcase
166     end
167 end
168 
169 
170 
171 // disbounce
172 always@(posedge wClk_1khz or negedge iRst_n) begin
173     if(!iRst_n) begin
174         oDval <= 0;
175         oKeyCode <= 5'd16;
176     end
177     else begin
178         if( rDval ) begin
179             oKeyCode <= rKeyCode;
180             oDval <= 1;
181         end
182         else begin
183             oKeyCode <= oKeyCode;
184             oDval <= 0;
185             
186         end
187     end
188 end
189 
190 endmodule