矩阵键盘控制数据存储，51单片机实现，写出代码

Sure! Here is an example code for controlling data storage using a matrix keypad with a 51 microcontroller:

#include <reg51.h>

// Define the rows and columns of the matrix keypad
sbit row1 = P1^0;
sbit row2 = P1^1;
sbit row3 = P1^2;
sbit row4 = P1^3;

sbit col1 = P1^4;
sbit col2 = P1^5;
sbit col3 = P1^6;
sbit col4 = P1^7;

// Function to scan the matrix keypad
unsigned char keypad_scan() {
    unsigned char key = 0xFF;
    
    // Scan the rows one by one
    row1 = 0; row2 = 1; row3 = 1; row4 = 1;
    if (col1 == 0) { key = '1'; }
    if (col2 == 0) { key = '2'; }
    if (col3 == 0) { key = '3'; }
    if (col4 == 0) { key = 'A'; }

    row1 = 1; row2 = 0; row3 = 1; row4 = 1;
    if (col1 == 0) { key = '4'; }
    if (col2 == 0) { key = '5'; }
    if (col3 == 0) { key = '6'; }
    if (col4 == 0) { key = 'B'; }

    row1 = 1; row2 = 1; row3 = 0; row4 = 1;
    if (col1 == 0) { key = '7'; }
    if (col2 == 0) { key = '8'; }
    if (col3 == 0) { key = '9'; }
    if (col4 == 0) { key = 'C'; }

    row1 = 1; row2 = 1; row3 = 1; row4 = 0;
    if (col1 == 0) { key = '*'; }
    if (col2 == 0) { key = '0'; }
    if (col3 == 0) { key = '#'; }
    if (col4 == 0) { key = 'D'; }

    return key;
}

void main() {
    unsigned char key;
    
    while(1) {
        key = keypad_scan();
        
        if (key != 0xFF) {
            // Store the key value in memory or perform any desired operations
            // For example, you can store it in an array or send it via serial communication
        }
    }
}

This code defines the rows and columns of the matrix keypad as `sbit` variables and implements a function `keypad_scan()` to scan the keypad. The function scans each row one by one and checks the column values to determine which key is pressed. The key value is then stored in a variable `key` and can be used for further processing, such as storing it in memory or performing any desired operations.

Please note that this is a basic example, and you may need to modify the code according to your specific requirements and hardware setup.