可以利用51单片机的EEPROM每次按下把数据存入，下次上电自动读取。下面的程序是读写EEPROM程序。仅供参考。
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#include "reg52.h"
#include "intrins.h"
typedef unsigned char BYTE;
typedef unsigned int WORD;
/*Declare SFR associated with the IAP */
sfr IAP_DATA = 0xC2; //Flash data register
sfr IAP_ADDRH = 0xC3; //Flash address HIGH
sfr IAP_ADDRL = 0xC4; //Flash address LOW
sfr IAP_CMD = 0xC5; //Flash command register
sfr IAP_TRIG = 0xC6; //Flash command trigger
sfr IAP_CONTR = 0xC7; //Flash control register
/*Define ISP/IAP/EEPROM command*/
#define CMD_IDLE 0 //Stand-By
#define CMD_READ 1 //Byte-Read
#define CMD_PROGRAM 2 //Byte-Program
#define CMD_ERASE 3 //Sector-Erase
/*Define ISP/IAP/EEPROM operation const for IAP_CONTR*/
//#define ENABLE_IAP 0x80 //if SYSCLK<30MHz
//#define ENABLE_IAP 0x81 //if SYSCLK<24MHz
#define ENABLE_IAP 0x82 //if SYSCLK<20MHz
//#define ENABLE_IAP 0x83 //if SYSCLK<12MHz
//Start address for STC15w204s EEPROM
#define IAP_ADDRESS1 0x0000 //型号不同，地址不同，具体见datasheet
#define IAP_ADDRESS2 0x0200
/*----------------------------
Disable ISP/IAP/EEPROM function
Make MCU in a safe state
----------------------------*/
void IapIdle()
{
IAP_CONTR = 0; //Close IAP function
IAP_CMD = 0; //Clear command to standby
IAP_TRIG = 0; //Clear trigger register
IAP_ADDRH = 0x80; //Data ptr point to non-EEPROM area
IAP_ADDRL = 0; //Clear IAP address to prevent misuse
}
/*----------------------------
Read one byte from ISP/IAP/EEPROM area
Input: addr (ISP/IAP/EEPROM address)
Output:Flash data
----------------------------*/
BYTE IapReadByte(WORD addr)
{
BYTE dat; //Data buffer
IAP_CONTR = ENABLE_IAP; //Open IAP function, and set wait time
IAP_CMD = CMD_READ; //Set ISP/IAP/EEPROM READ command
IAP_ADDRL = addr; //Set ISP/IAP/EEPROM address low
IAP_ADDRH = addr >> 8; //Set ISP/IAP/EEPROM address high
IAP_TRIG = 0x5a; //Send trigger command1 (0x46)
IAP_TRIG = 0xa5; //Send trigger command2 (0xb9)
_nop_(); //MCU will hold here until ISP/IAP/EEPROM operation complete
dat = IAP_DATA; //Read ISP/IAP/EEPROM data
IapIdle(); //Close ISP/IAP/EEPROM function
return dat; //Return Flash data
}
/*----------------------------
Program one byte to ISP/IAP/EEPROM area
Input: addr (ISP/IAP/EEPROM address)
dat (ISP/IAP/EEPROM data)
Output:-
----------------------------*/
void IapProgramByte(WORD addr, BYTE dat)
{
IAP_CONTR = ENABLE_IAP; //Open IAP function, and set wait time
IAP_CMD = CMD_PROGRAM; //Set ISP/IAP/EEPROM PROGRAM command
IAP_ADDRL = addr; //Set ISP/IAP/EEPROM address low
IAP_ADDRH = addr >> 8; //Set ISP/IAP/EEPROM address high
IAP_DATA = dat; //Write ISP/IAP/EEPROM data
IAP_TRIG = 0x5a; //Send trigger command1 (0x46)
IAP_TRIG = 0xa5; //Send trigger command2 (0xb9)
_nop_(); //MCU will hold here until ISP/IAP/EEPROM operation complete
IapIdle();
}
/*----------------------------
Erase one sector area
Input: addr (ISP/IAP/EEPROM address)
Output:-
----------------------------*/
void IapEraseSector(WORD addr)
{
IAP_CONTR = ENABLE_IAP; //Open IAP function, and set wait time
IAP_CMD = CMD_ERASE; //Set ISP/IAP/EEPROM ERASE command
IAP_ADDRL = addr; //Set ISP/IAP/EEPROM address low
IAP_ADDRH = addr >> 8; //Set ISP/IAP/EEPROM address high
IAP_TRIG = 0x5a; //Send trigger command1 (0x46)
IAP_TRIG = 0xa5; //Send trigger command2 (0xb9)
_nop_(); //MCU will hold here until ISP/IAP/EEPROM operation complete
IapIdle();
} |
