Datasheet

SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
48
Figure 10-1. Typical Cortex-M3 implementation
The Cortex-M3 processor is built on a high-performance processor core, with a 3-stage pipeline Harvard
architecture, making it ideal for demanding embedded applications. The processor delivers exceptional power
efficiency through an efficient instruction set and extensively optimized design, providing high-end processing
hardware including single-cycle 32x32 multiplication and dedicated hardware division.
To facilitate the design of cost-sensitive devices, the Cortex-M3 processor implements tightly-coupled system
components that reduce processor area while significantly improving interrupt handling and system debug
capabilities. The Cortex-M3 processor implements a version of the Thumb
®
instruction set, ensuring high code
density and reduced program memory requirements. The Cortex-M3 instruction set provides the exceptional
performance expected of a modern 32-bit architecture, with the high code density of 8-bit and 16-bit
microcontrollers.
The Cortex-M3 processor closely integrates a configurable nested interrupt controller (NVIC), to deliver industry-
leading interrupt performance. The NVIC provides up to 16 interrupt priority levels. The tight integration of the
processor core and NVIC provides fast execution of interrupt service routines (ISRs), dramatically reducing the
interrupt latency. This is achieved through the hardware stacking of registers, and the ability to suspend load-
multiple and store-multiple operations. Interrupt handlers do not require any assembler stubs, removing any code
overhead from the ISRs. Tail-chaining optimization also significantly reduces the overhead when switching from
one ISR to another.
To optimize low-power designs, the NVIC integrates with the sleep modes, that include a deep sleep function that
enables the entire device to be rapidly powered down.
10.3.1 System level interface
The Cortex-M3 processor provides multiple interfaces using AMBA
®
technology to provide high speed, low latency
memory accesses. It supports unaligned data accesses and implements atomic bit manipulation that enables
faster peripheral controls, system spinlocks and thread-safe Boolean data handling.
The Cortex-M3 processor has a memory protection unit (MPU) that provides fine grain memory control, enabling
applications to implement security privilege levels, separating code, data and stack on a task-by-task basis. Such
requirements are becoming critical in many embedded applications.
Processor
Core
NVIC
Debug
Access
Port
Memory
Protection Unit
Serial
Wire
Viewer
Bus Matrix
Code
Interface
SRAM and
Peripheral Interface
Data
Watchpoints
Flash
Patch
Cortex-M3
Processor