将所有keypad、display、main的.c和.h文件以及包括其所需要的所有代码都写出来，要求详细无错

基于所提供的代码片段，我们可以构造一个基本框架用于实现STC32G8K64单片机上使用矩阵键盘控制共阴极LED数码管的数值变化的功能。以下是`keypad.c`, `keypad.h`, `display.c`, `display.h`, 和`main.c`文件的大致结构及其所需的部分代码：

### keypad.h

#ifndef KEYPAD_H_
#define KEYPAD_H_

extern unsigned char keyscan(unsigned char row[], unsigned char col[]);

#endif /* KEYPAD_H_ */

### keypad.c

#include "keypad.h"
#include <reg52.h>

unsigned char keyscan(unsigned char row[4], unsigned char col[3]) {
    unsigned char i;
    static unsigned char last_key = 0; 
    unsigned char current_key = 0;

    for(i = 0; i < 4; ++i)
        P2 = 0xF0 | (1<< (i + 4)); // Set rows as output and columns as input
    
    for(i = 0; i < 3; ++i){
        if(!(P2 & (1 << (i+6)))){
            switch(i){
                case 0:
                    if(row == 0) current_key = 1; 
                    else if(row == 1) current_key = 10;
                    else if(row == 2) current_key = 11;
                    break;
                default: 
                    current_key = i*3 + row + 2; // Assuming a specific layout is defined elsewhere
            }
            break;
        }
    }

    if(current_key && current_key != last_key){ // Detect changes in the keys pressed
        delay(20); // Debounce delay
        if(keyscan(row, col) == current_key) { // Check again to confirm it wasn't just a bounce
            last_key = current_key;
            return current_key;
        }   
    }
    
    return 0; // No key was pressed or the same key remains pressed
}

### display.h

#ifndef DISPLAY_H_
#define DISPLAY_H_

void display(unsigned short int num);
extern const unsigned char digcode[];

#endif /* DISPLAY_H_ */

### display.c

#include "display.h"
#include <reg52.h>
sbit conf1 = P0^0;
sbit conf2 = P0^1;
sbit conf3 = P0^2;

const unsigned char digcode[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};

void display(unsigned short int number) {
    u8 d2, d1, d0;
    d2 = (number / 100);
    d1 = ((number / 10) % 10);
    d0 = (number % 10);
    
    conf1 = 0;
    P1 = digcode[d2];
    conf1 = 1;
    
    conf2 = 0;
    P1 = digcode[d1];
    conf2 = 1;
    
    conf3 = 0;
    P1 = digcode[d0];
    conf3 = 1;
}

// Timer1 interrupt function should call this display function periodically.

### main.c

#include <reg52.h>
#include "keypad.h"
#include "display.h"

unsigned char row[4] = {P2_0, P2_1, P2_2, P2_3};
unsigned char col[3] = {P2_4, P2_5, P2_6};
unsigned short int display_num = 0;

void main() {
    TMOD = 0x10;   // Set timer 1 in mode 1
    TH1 = (65536 - (SystemClock / 2 / 50)) / 256;  // Adjust according to your system clock
    TL1 = (65536 - (SystemClock / 2 / 50)) % 256;
    EA = 1;         // Enable interrupts
    ET1 = 1;        // Enable timer 1 interrupts
    TR1 = 1;        // Start timer 1

    while(1) {
        unsigned char key = keyscan(row, col);
        if(key > 0) {
            if(display_num < 11) display_num += key;
            else display_num = key; // Reset to new value if overflows
        }
    }
}

void timer1_isr() interrupt 3 {
    static unsigned long count = 0;
    TH1 = (65536 - (SystemClock / 2 / 50)) / 256;
    TL1 = (65536 - (SystemClock / 2 / 50)) % 256;
    if(count++ % 10 == 0) display(display_num); // Display every 10th tick for example purposes
}

注意：以上代码仅提供了一个概念性的实现方案，并未考虑所有的细节如精确延时、错误处理等。实际应用前还需要进一步测试和完善。此外，“digcode”数组定义应该更完整地反映各个数字的实际编码，且需确认P1端口是否真的能够直接用于输出显示（考虑到可能的硬件限制）。