1Chapter 0 Subroutines and Stacks
William Hohl · 2009
Subroutines, which are routines dedicated to focused or shorter tasks, occur in nearly all embedded code, often to perform initialization routines or to handle algorithms that require handcrafted assembly. You’re very likely to write subroutines when you come across a large problem to solve. The notion of divide-and-conquer aptly applies to writing assembly code-it’s just easier to get your head around a problem by describing it as a sequence of events, worrying about the low-level details when you write the event itself. For example, you could break a large program that handles a motor controller into something that looks like and then write each of the smaller tasks as subroutines. Even if you’re coding at a high level, say in C or C++, it’s natural to break down a large task into smaller blocks or functions, each function being a routine that can be called from a main routine.