ATmega64A
0xFF to the register gives the highest available frequency. The calibrated Oscillator is used to
time EEPROM and Flash access. If EEPROM or Flash is written, do not calibrate to more than
10% above the nominal frequency. Otherwise, the EEPROM or Flash write may fail. Note that
the Oscillator is intended for calibration to 1.0, 2.0, 4.0, or 8.0 MHz. Tuning to other values is not
guaranteed, as indicated in Table 8-10.
Table 8-10. Internal RC Oscillator Frequency Range
Min Frequency in Percentage of
Nominal Frequency (%)
Max Frequency in Percentage of
Nominal Frequency (%)
OSCCAL Value
0x00
50
75
100
150
200
0x7F
0xFF
100
45
8160C–AVR–07/09
ATMEL [ ATMEL ]
