Version 1.x Oscillators

This version is the earliest internal RC oscillator for AVR that can be calibrated. It is offered with frequencies ranging from 1.2 to 1.6MHz. The calibration byte is stored in the Signature Row, but is not automatically loaded at start-up. The loading of the OSCCAL register must be handled at run-time by the firmware. The oscillator frequency is highly dependent on operating voltage and temperature in this version.