Migrating from Assembly to C for 8-bit Microcontrollers

Assembly language has typically been the programming language of choice for embedded system programmers. Looking into the 8-bit microcontroller offerings from different vendors, one finds that these microcontrollers can be programmed using the high-level C programming language as well as assembly. Some microcontrollers have even been designed with high-level languages in mind as a means of programming, thus alleviating common high-level language bottlenecks. The embedded source code examples found in this paper will be based on ATMEL Corporation's 8-bit AVR microcontroller, which was designed for programming using the high-level C language. In order to program microcontrollers using the C language a compiler is required to translate the high-level language in to low-level machine instructions the microcontroller can execute. Utilizing a high-level language when programming microcontrollers offers key advantages over low-level languages while introducing a single 'gotcha' that can be overcome with careful attention and planning.