2.1 Introduction to the 8-bit AVR Toolchains

Microchip distributes two toolchains that target 8-bit AVR devices, these being the AVR® 8-bit GNU Toolchain (AVR-GCC) and the MPLAB® XC8 C Compiler (MPLAB XC8). When targeting AVR devices, both toolchains use applications based on the open-source GCC C/C++ compiler developed by GNU (www.gnu.org). Both compilers target all 8-bit AVR devices, although the MPLAB XC8 compiler additionally targets all 8-bit PIC devices. The compilers differ in their features that support ease of coding and optimization, as well as their requirement of a purchased license to operate with full optimization, as summarized in the following table.