ARMv7M

ARMv7-M is the ARMv7 architecture profile designed for the Cortex-M series of microcontrollers, including Cortex-M3, Cortex-M4, and Cortex-M7 cores. It defines a 32-bit RISC core that executes Thumb-2 instructions, providing a compact yet capable instruction set for embedded real-time control. The architecture emphasizes deterministic timing, low interrupt latency, and energy efficiency, making it suitable for a wide range of automotive, consumer, and industrial devices.

Key features include a Thumb-2 unified instruction set and a privilege model with Thread and Handler modes, allowing privileged and unprivileged operation controlled by the CONTROL register. It provides a fast, nested vectored interrupt controller (NVIC) for low-latency interrupt handling, supports MSP and PSP stack pointers, and uses a simple memory model with an optional memory protection unit (MPU) instead of a full MMU. The LDREX/STREX exclusive load/store instructions support atomic operations, aiding synchronization in concurrent software.

Many Cortex-M4 and Cortex-M7 variants offer an optional single-precision floating-point unit (FPU) and, in some devices, digital signal processing extensions to boost performance on numeric workloads. Debug and trace facilities, including ITM, DWT, and, on some variants, ETM, are available through standard debug interfaces such as SWD.

The ARMv7-M design emphasizes simplicity and deterministic behavior, with a focus on low power and predictable interrupts, making it a dominant choice for embedded systems requiring real-time control and robust software protection. It remains widely supported by toolchains, middleware, and vendor ecosystems across a broad range of microcontroller products.