12.2 Variables In Data Space Memory

Most variables are ultimately positioned into the data space memory. The exceptions are non-auto variables which are qualified as const and may be placed in the program memory space.

Due to the fundamentally different way in which auto variables and non-auto variables are allocated memory, they are discussed separately. To use the C language terminology, these two groups of variables are those with ‘automatic storage duration’ and those with ‘permanent storage duration’, respectively.

In terms of memory allocation, variables are allocated space based on whether it is an auto or not; hence the grouping in the following sections.