6.4. Data Type Conversion
The Cortex®-M processors support a number of instructions for converting data between different data types.
6.4.1. Conversion of Data Size
On compilers for ARM®
architecture, different data types have different sizes. A number of commonly used data types and its corresponding sizes on ARM compilers are shown in the following table (Table 6.7
Size of commonly used data types in C language for ARM® architecture
|C data type||Number of bits|
|“char”, “unsigned char”||8|
|“enum”||8/16/32 (Smallest is chosen)|
|“short”, “unsigned short”||16|
|“int”, “unsigned int”||32|
|“long”, “unsigned long”||32|
When converting a data value from one type to another type with a larger size, we need to sign extend or zero extend it. A number of instructions are ...
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