The Definitive Guide to the ARM Cortex-M0

Appendix C. CMSIS Quick Reference

The Cortex Microcontroller Software Interface Standard (CMSIS) contains a number of standardized functions:

• Core peripheral access functions

• Core register access functions

• Special instruction access functions

This appendix covers the basic information about these functions and other information related to using the CMSIS.

Data Type

The CMSIS uses standard data types defined in “stdint.h” (Table C.1).

Table C.1 Standard Data Types Used in CMSIS

Type	Data
uint32_t	Unsigned 32-bit integer
uint16_t	Unsigned 16-bit integer
uint8_t	Unsigned 8-bit integer

Exception Enumeration

Instead of using integer values for exception types, the CMSIS uses the IRQn enumeration to identify exceptions. The CMSIS defines the following enumeration ...