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SAM4CM Series [DATASHEET]
Atmel-11203C-ATARM-SAM4CM32-SAM4CM16-SAM4CM8-Datasheet_06-Oct-14
12.4.1.17Exceptions and Interrupts
The Cortex-M4 processor supports interrupts and system exceptions. The processor and the
Nested Vectored
Interrupt Controller
(NVIC) prioritize and handle all exceptions. An exception changes the normal flow of software
control. The processor uses the Handler mode to handle all exceptions except for reset. See
“Exception Entry”
and
“Exception Return”
for more information.
The NVIC registers control interrupt handling. See
“Nested Vectored Interrupt Controller (NVIC)”
for more
information.
12.4.1.18Data Types
The processor supports the following data types:
32-bit words
16-bit halfwords
8-bit bytes
The processor manages all data memory accesses as little-endian. Instruction memory and
Private
Peripheral Bus
(PPB) accesses are always little-endian. See
“Memory Regions, Types and Attributes”
for
more information.
12.4.1.19 Cortex Microcontroller Software Interface Standard (CMSIS)
For a Cortex-M4 microcontroller system, the
Cortex Microcontroller Software Interface Standard
(CMSIS) defines:
A common way to:
Access peripheral registers
Define exception vectors
The names of:
The registers of the core peripherals
The core exception vectors
A device-independent interface for RTOS kernels, including a debug channel.
The CMSIS includes address definitions and data structures for the core peripherals in the Cortex-M4 processor.
The CMSIS simplifies the software development by enabling the reuse of template code and the combination of
CMSIS-compliant software components from various middleware vendors. Software vendors can expand the
CMSIS to include their peripheral definitions and access functions for those peripherals.
This document includes the register names defined by the CMSIS, and gives short descriptions of the CMSIS
functions that address the processor core and the core peripherals.
Note:
This document uses the register short names defined by the CMSIS. In a few cases, these differ from the architectural
short names that might be used in other documents.
The following sections give more information about the CMSIS:
Section 12.5.3 “Power Management Programming Hints”
Section 12.6.2 “CMSIS Functions”
Section 12.8.2.1 “NVIC Programming Hints”
.