Cortex-M3 Processor (Reference Material)
UG0331 User Guide Revision 15.0
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Cortex-M3 Processor (Reference Material)
The Cortex-M3 processor is a high performance 32-bit processor designed for the microcontroller
market. It offers significant benefits to developers, including:
•
Outstanding processing performance combined with fast interrupt handling
•
Enhanced system debug with extensive breakpoint and trace capabilities
•
Efficient processor core, system, and memories
•
Ultra-low power consumption with integrated Sleep modes
•
Platform security robustness, with optional integrated memory protection unit (MPU)
Figure 4 •
Cortex-M3 Processor 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 a range of single-cycle and SIMD multiplication and multiply-with-
accumulate capabilities, saturating arithmetic 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
based on Thumb-2 technology, ensuring high code density and reduced program memory requirements.
The Cortex-M3 processor 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 includes a non-maskable interrupt (NMI), and provides
up to 256 interrupt priority levels. NVIC in SmartFusion2 SoC FPGA MSS is set to have 83 interrupts
(including non-maskable interrupt).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 wrapping in assembly code, removing any
Processor
Core
Embedded
Trace Macrocell
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
WIC