EEPROM ansprechen AT89C61CC03

// Read one Byte from the EEPROM. Can Interrupt must be disabled, because

// XDATA Acess is directed to the EEPROM.

uchar eeReadByte (uint off)

{

   register uchar ret;

   EA = 0;                      // No Interrupts

   AUXR |= 0x20;                // Stretch Memory Cycle

   EECON = 0x02;                // Enable EEPROM Access

   ret = *((uchar xdata *)(off));

   EECON = 0x00;                // Disable EEPROM Access

   AUXR &= ~0x20;               // UnStretch Memory Cycle

   EA = 1;                      // Interrupts On

   return (ret);

}

// Write one Byte to the EEPROM. Can Interrupt must be disabled, because

// XDATA Acess is directed to the EEPROM.

fbit eeWriteByte (uint off, uchar val)

{

   EA = 0;                      // No Interrupts

   AUXR |= 0x20;                // Stretch Memory Cycle

   EECON = 0x02;                // Enable EEPROM Access

   *((uchar xdata *)(off)) = val;

   EECON = 0x00;                // Disable EEPROM Access

   EECON = 0x50;                // Start EEPROM Programming

   EECON = 0xa0;                //            "

   AUXR &= ~0x20;               // UnStretch Memory Cycle

   EA = 1;                      // Interrupts On

   while (EECON & 0x01) ;       // Wait for Programming Ready

   return (1);

}