AVR EEPROM问题

Question

当我使用变形模拟下面的程序，该EEPROM不会改变，而且当我添加EECR观看EEPE将没有设置，整个计划是在这里：

#include <inttypes.h> 
#include <avr/io.h> 
#include <avr/interrupt.h> 
#include <avr/sleep.h> 
#include <util/delay.h> 

void writeEEPROM(unsigned char address,char data){ 
    while(EECR & (1<<EEPE)); //wait for previus writing; 
    EECR = ((0<<EEPM1)|(0<<EEPM0)); 
    //EECR=0; 
    EEAR = address; //set address to eeprom address register 
    EEDR = data; 
    cli(); 
    EECR |= (1<<EEMPE); 
    EECR |= (1<<EEPE); 
    while(EECR & (1<<EEPE)); //wait for previus writing; 
    EECR |= (1<<EEMPE); 
    EECR |= (1<<EEPE); 
    sei(); 
} 

char readEEPROM(unsigned char address){ 
    while(EECR & (1<<EEPE)); //wait for previous write operation 
    EEAR=0; 
    EEAR |= address; 
    EECR=0; 
    EECR |= 1; //set bit0 
    return EEDR; 
} 

int main() 
{ 
    // Write your code here 
    char ret=0; 
    writeEEPROM(1,9); 
    _delay_ms(100); 
    ret=readEEPROM(1); 
    if(ret==9){ 
    DDRB=0xff; 
    PORTB=0xff; 
    } 
    while (1) 
    ; 
    return 0; 
} 

在调用writeEEPROM数据时不会存储到eeprom。

Answer 1

这是从源代码伴随文件集到AVR103 AVR EEPROM Application Note，来自设备制造商的权威发布。

char EEPROM_GetChar(unsigned int addr) 
{ 
    do {} while(EECR & (1<<EEPE)); // Wait for completion of previous write. 
    EEAR = addr; // Set EEPROM address register. 
    EECR = (1<<EERE); // Start EEPROM read operation. 
    return EEDR; // Return the byte read from EEPROM. 
} 


void EEPROM_PutChar(unsigned int addr, char new_value) 
{ 
    char old_value; // Old EEPROM value. 
    char diff_mask; // Difference mask, i.e. old value XOR new value. 

    unsigned char old_interrupt; // Stores interrupt flag while programming. 
    old_interrupt = __save_interrupt(); // Save interrupt flag state. 
    __disable_interrupt(); // Ensure atomic operation for the write operation. 

    do {} while(EECR & (1<<EEPE)); // Wait for completion of previous write. 
    #ifndef EEPROM_IGNORE_SELFPROG 
    do {} while(SPMCSR & (1<<SELFPRGEN)); // Wait for completion of SPM. 
    #endif 

    EEAR = addr; // Set EEPROM address register. 
    EECR = (1<<EERE); // Start EEPROM read operation. 
    old_value = EEDR; // Get old EEPROM value. 
    diff_mask = old_value^new_value; // Get bit differences. 

    // Check if any bits are changed to '1' in the new value. 
    if(diff_mask & new_value) { 
     // Now we know that _some_ bits need to be erased to '1'. 

     // Check if any bits in the new value are '0'. 
     if(new_value != 0xff) { 
      // Now we know that some bits need to be programmed to '0' also. 

      EEDR = new_value; // Set EEPROM data register. 
      EECR = (1<<EEMPE) | // Set Master Write Enable bit... 
        (0<<EEPM1) | (0<<EEPM0); // ...and Erase+Write mode. 
      EECR |= (1<<EEPE); // Start Erase+Write operation. 
     } else { 
      // Now we know that all bits should be erased. 

      EECR = (1<<EEMPE) | // Set Master Write Enable bit... 
        (1<<EEPM0); // ...and Erase-only mode. 
      EECR |= (1<<EEPE); // Start Erase-only operation. 
     } 
    } else { 
     // Now we know that _no_ bits need to be erased to '1'. 

     // Check if any bits are changed from '1' in the old value. 
     if(diff_mask) { 
      // Now we know that _some_ bits need to the programmed to '0'. 

      EEDR = new_value; // Set EEPROM data register. 
      EECR = (1<<EEMPE) | // Set Master Write Enable bit... 
        (1<<EEPM1); // ...and Write-only mode. 
      EECR |= (1<<EEPE); // Start Write-only operation. 
     } 
    } 

    __restore_interrupt(old_interrupt); // Restore interrupt flag state. 
} 


void main() 
{ 
    char t; // Temporary byte. 
    unsigned int addr = 0x10; // EEPROM address to use. 

    // Test the EEPROM_GetChar() function. 
    t = EEPROM_GetChar(addr); 

    // Try erasing the whole byte. 
    EEPROM_PutChar(addr, 0xff); 

    // Try changing a few bits to '0'. 
    EEPROM_PutChar(addr, 0x0f); 

    // Try changing bits both ways. 
    EEPROM_PutChar(addr, 0xf0); 

    // Try changing nothing. 
    EEPROM_PutChar(addr, 0xf0); 

    // Restore old value. 
    EEPROM_PutChar(addr, t); 

    for(;;); // Loop forever. 
}