CortexM3

Cortex-M3 is a 32-bit ARM processor core designed for embedded microcontrollers and a member of the ARM Cortex-M family. It implements the ARMv7-M architecture and uses the Thumb-2 instruction set, which combines 16-bit and 32-bit instructions to deliver compact code with efficient performance for embedded applications.

A central feature of the Cortex-M3 is the Nested Vectored Interrupt Controller (NVIC), which provides low-latency, deterministic interrupt handling and programmable interrupt priorities to support real-time responsiveness. The core also includes an optional Memory Protection Unit (MPU) to help isolate tasks and improve safety in embedded systems. Debug and trace capabilities are available through standard interfaces such as Serial Wire Debug (SWD) and JTAG, with optional trace components in some devices.

In terms of performance and integration, Cortex-M3 cores are designed for low power consumption and small silicon area, and are commonly implemented in devices ranging from tens to hundreds of megahertz depending on the specific microcontroller. Many variants may include on-chip caches or tightly coupled memory to reduce latency and improve determinism for real-time tasks.

Development and ecosystem support for Cortex-M3 is broad, with extensive toolchain availability (GCC, LLVM, Keil, IAR) and CMSIS libraries that facilitate software portability. The architecture is widely supported by real-time operating systems such as FreeRTOS, Zephyr, and RTX. Typical applications span automotive control, consumer electronics, industrial automation, and Internet of Things devices, where deterministic timing, reliability, and a small footprint are important.