verilog电子琴4*4

以下是一个简单的Verilog代码，实现了一个4 * 4键盘电子琴的功能。该代码使用一个FPGA板上的4个LED灯，用于模拟音乐的输出。

module keyboard_electronic_piano(
    input [3:0] row,
    output reg [3:0] col,
    output reg [3:0] sound
);

//定义键盘的状态
reg [3:0] key_state;

//定义音乐的频率（C4～B4）
reg [3:0] frequency [0:11] = {16'h1F40, 16'h1D51, 16'h1B71, 16'h19A9, 16'h17F4, 16'h164B, 16'h14B1, 16'h1327, 16'h11AE, 16'h1046, 16'h0EF0, 16'h0DAE};

//定义键盘的映射表
reg [3:0] key_map [0:3][0:3] = {{4'h1, 4'h2, 4'h3, 4'hA},
                                 {4'h4, 4'h5, 4'h6, 4'hB},
                                 {4'h7, 4'h8, 4'h9, 4'hC},
                                 {4'hE, 4'h0, 4'hF, 4'hD}};

//读取键盘的状态
always @(row)
begin
    key_state <= {col, ~row};
end

//检测按下的键
always @(*)
begin
    case(key_state)
        4'h0E: begin col <= 4'hE; sound <= frequency[0]; end
        4'h0D: begin col <= 4'hD; sound <= frequency[1]; end
        4'h0B: begin col <= 4'hB; sound <= frequency[2]; end
        4'h07: begin col <= 4'h7; sound <= frequency[3]; end
        4'h0C: begin col <= 4'hC; sound <= frequency[4]; end
        4'h09: begin col <= 4'h9; sound <= frequency[5]; end
        4'h05: begin col <= 4'h5; sound <= frequency[6]; end
        4'h02: begin col <= 4'h2; sound <= frequency[7]; end
        4'h00: begin col <= 4'h0; sound <= frequency[8]; end
        4'h01: begin col <= 4'h1; sound <= frequency[9]; end
        4'h03: begin col <= 4'h3; sound <= frequency[10]; end
        4'h06: begin col <= 4'h6; sound <= frequency[11]; end
        default: begin col <= 4'hF; sound <= 0; end
    endcase
end

endmodule

该代码使用了一个4 * 4的键盘矩阵，并将键盘的状态存储在一个4位的寄存器中。然后，使用一个always块来检测按下的键，并将其映射到相应的音乐频率。最后，将LED灯用作音乐输出，以便模拟电子琴的声音。