Скачивается с оф. сайта.
EWAVR-EV Version: 12_WIN
News in the current product version
Version 5.10 of IAR Embedded Workbench for AVR includes the following new and enhanced functionality:
Support for the new Atmel XMEGA device family
Support has been added for the new Atmel XMEGA device family.
New device support
Support has been added for the following new devices: ATtiny48, ATtiny88, ATtiny23U, ATtiny43U, ATtiny167, ATmega1284P, ATmega32C1, ATmega32M1, ATmega32U4, ATxmega128A1, ATxmega64A1.
New DLIB runtime library
A new version of the DLIB runtime library is used in this version of the product.