Atmel AVR543: Migration from
ATmega645/6450/649/6490 to
ATmega645A/6450A/649A/6490A
1 Introduction
The Atmel
®
ATmega645A/6450A/649A/6490A is a functionally identical, drop-in
replacement for the Atmel ATmega645/6450/649/6490. All devices are subject to
the same qualification process and same set of production tests, but some
electrical characteristics differ.
ATmega645/6450/649/6490 and ATmega645A/6450A/649A/6490A have separate
datasheets. This application note outlines the differences between the two devices
and between the datasheets. There is also a detailed change log to assist the user
at the end of the ATmega645A/6450A/649A/6490A datasheet. Remember to
always use the latest revision of the device datasheet.
Minor differences in typical characteristics are not discussed in this document as
long as the low and high limits remain the same. For detailed information about the
typical characteristics, see sections “Electrical Characteristics” and “Typical
Characteristics” of the device datasheets.
Note: This application note serves as a guide to ease migration. For complete
device details, always refer to the most recent version of the
ATmega645A/6450A/649A/6490A datasheet.
8-bit Atmel
Microcontrollers
Application Note
Rev. 8423A-AVR-11/11
