PS2键盘编码Verilog源程序.doc

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1、Four short words sum up what has lifted most successful individuals above the crowd: a little bit more.-author-datePS2键盘编码Verilog源程序PS2键盘编码Verilog源程序PS2键盘编码Verilog源程序之前探讨过PS/2键盘编解码以及数据传输协议，这次自己动手实现了利用FPGA接收键盘编码，然后通过串口传输到PC。做的比较简单，只是通过FPGA把大写字母A-Z转换成相应的ASCII码，只要字母按键被按下，就能在串口调试助手里显示相应大写字母。下面就共享代码吧！ 除了

2、顶层模块，三个底层模块分别为PS/2传输处理模块、串口传输模块以及串口波特率选择模块（下面只给出顶层模块和PS/2传输处理模块的verilog代码）。 module ps2_key(clk,rst_n,ps2k_clk,ps2k_data,rs232_tx); input clk; /50M时钟信号 input rst_n; /复位信号 input ps2k_clk; /PS2接口时钟信号 input ps2k_data; /PS2接口数据信号 output rs232_tx; / RS232发送数据信号 wire7:0 ps2_byte; / 1byte键值 wire ps2_state;

3、/按键状态标志位 wire bps_start; /接收到数据后，波特率时钟启动信号置位 wire clk_bps; / clk_bps的高电平为接收或者发送数据位的中间采样点 ps2scan ps2scan( .clk(clk), /按键扫描模块 .rst_n(rst_n), .ps2k_clk(ps2k_clk), .ps2k_data(ps2k_data), .ps2_byte(ps2_byte), .ps2_state(ps2_state) ); speed_select speed_select( .clk(clk), .rst_n(rst_n), .bps_start(bps_st

4、art), .clk_bps(clk_bps) ); my_uart_tx my_uart_tx( .clk(clk), .rst_n(rst_n), .clk_bps(clk_bps), .rx_data(ps2_byte), .rx_int(ps2_state), .rs232_tx(rs232_tx), .bps_start(bps_start) ); Endmodule module ps2scan(clk,rst_n,ps2k_clk,ps2k_data,ps2_byte,ps2_state); input clk; /50M时钟信号 input rst_n; /复位信号 input

5、 ps2k_clk; /PS2接口时钟信号 input ps2k_data; /PS2接口数据信号 output7:0 ps2_byte; / 1byte键值，只做简单的按键扫描 output ps2_state; /键盘当前状态，ps2_state=1表示有键被按下 /- reg ps2k_clk_r0,ps2k_clk_r1,ps2k_clk_r2; /ps2k_clk状态寄存器 /wire pos_ps2k_clk; / ps2k_clk上升沿标志位 wire neg_ps2k_clk; / ps2k_clk下降沿标志位 always (posedge clk or negedge rs

6、t_n) begin if(!rst_n) begin ps2k_clk_r0 = 1b0; ps2k_clk_r1 = 1b0; ps2k_clk_r2 = 1b0; end else begin /锁存状态，进行滤波 ps2k_clk_r0 = ps2k_clk; ps2k_clk_r1 = ps2k_clk_r0; ps2k_clk_r2 = ps2k_clk_r1; end end assign neg_ps2k_clk = ps2k_clk_r1 & ps2k_clk_r2; /下降沿 /- reg7:0 ps2_byte_r; /PC接收来自PS2的一个字节数据存储器 reg7:0

7、 temp_data; /当前接收数据寄存器 reg3:0 num; /计数寄存器 always (posedge clk or negedge rst_n) begin if(!rst_n) begin num = 4d0; temp_data = 8d0; end else if(neg_ps2k_clk) begin /检测到ps2k_clk的下降沿case (num) 4d0: num = num+1b1; 4d1: begin num = num+1b1; temp_data0 = ps2k_data; /bit0 end 4d2: begin num = num+1b1; temp

8、_data1 = ps2k_data; /bit1 end 4d3: begin num = num+1b1; temp_data2 = ps2k_data; /bit2 end 4d4: begin num = num+1b1; temp_data3 = ps2k_data; /bit3 end 4d5: begin num = num+1b1; temp_data4 = ps2k_data; /bit4 end 4d6: begin num = num+1b1; temp_data5 = ps2k_data; /bit5 end 4d7: begin num = num+1b1; temp

9、_data6 = ps2k_data; /bit6 end 4d8: begin num = num+1b1; temp_data7 = ps2k_data; /bit7 end 4d9: begin num = num+1b1; /奇偶校验位，不做处理 end 4d10: begin num = 4d0; / num清零 end default: ; endcase end end reg key_f0; /松键标志位，置1表示接收到数据8hf0，再接收到下一个数据后清零 reg ps2_state_r; /键盘当前状态，ps2_state_r=1表示有键被按下 always (posedg

10、e clk or negedge rst_n) begin /接收数据的相应处理，这里只对1byte的键值进行处理 if(!rst_n) begin key_f0 = 1b0; ps2_state_r = 1b0; end else if(num=4d10) begin /刚传送完一个字节数据 if(temp_data = 8hf0) key_f0 = 1b1; else begin if(!key_f0) begin /说明有键按下 ps2_state_r = 1b1; ps2_byte_r = temp_data; /锁存当前键值 end else begin ps2_state_r =

11、1b0; key_f0 = 1b0; end end end end reg7:0 ps2_asci; /接收数据的相应ASCII码 always (ps2_byte_r) begin case (ps2_byte_r) /键值转换为ASCII码，这里做的比较简单，只处理字母 8h15: ps2_asci = 8h51; /Q 8h1d: ps2_asci = 8h57; /W 8h24: ps2_asci = 8h45; /E 8h2d: ps2_asci = 8h52; /R 8h2c: ps2_asci = 8h54; /T 8h35: ps2_asci = 8h59; /Y 8h3c:

12、 ps2_asci = 8h55; /U 8h43: ps2_asci = 8h49; /I 8h44: ps2_asci = 8h4f; /O 8h4d: ps2_asci = 8h50; /P 8h1c: ps2_asci = 8h41; /A 8h1b: ps2_asci = 8h53; /S 8h23: ps2_asci = 8h44; /D 8h2b: ps2_asci = 8h46; /F 8h34: ps2_asci = 8h47; /G 8h33: ps2_asci = 8h48; /H 8h3b: ps2_asci = 8h4a; /J 8h42: ps2_asci = 8h

13、4b; /K 8h4b: ps2_asci = 8h4c; /L 8h1z: ps2_asci = 8h5a; /Z 8h22: ps2_asci = 8h58; /X 8h21: ps2_asci = 8h43; /C 8h2a: ps2_asci = 8h56; /V 8h32: ps2_asci = 8h42; /B 8h31: ps2_asci = 8h4e; /N 8h3a: ps2_asci = 8h4d; /M default: ; endcase end assign ps2_byte = ps2_asci; assign ps2_state = ps2_state_r; endmodule-