变形杆菌中的AVR EEPROM问题

Question

当我使用 Proteus 模拟以下程序时，EEPROM 不会改变，而且当我添加 EECR 观看时，EEPE 也不会设置，整个程序在这里：

#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;
}

调用时，写入EEPROM数据不会存储到EEPROM。

Answer 1

本文来自源代码配套文件集 AVR103 AVR EEPROM 应用笔记，来自设备制造商的权威出版物。

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.
}