The ARM Cortex-M7 is a high-performance, energy-efficient 32-bit processor core designed for advanced embedded applications. It is based on the ARMv7-M architecture and is the highest performance core in the Cortex-M series of embedded cores.
The Cortex-M7 core is designed to deliver high DSP/floating point performance together with advanced features for real-time applications. It provides substantial improvements over previous Cortex-M generations including significantly higher performance and the addition of optional Floating Point Unit (FPU), Memory Protection Unit (MPU), and full Cache Coherence support.
Key Features of Cortex-M7
- Speed and Performance – Up to 300 MHz operation frequency, 3.6 CoreMark/MHz efficiency.
- DSP Capabilities – Optional single and double precision Floating Point Unit (FPU).
- Advanced Peripherals – Embedded Trace Macrocell (ETM) and Micro Trace Buffer (MTB) for real-time system debugging.
- Memory Architecture – Supports tightly-coupled memory (TCM) for low-latency access. Optional MPU and bus architecture supports Cache Coherent systems.
- Power Management – Dynamic voltage scaling and low-power modes for energy-efficient operation.
- Security Features – Optional TrustZone security extensions and Cryptography extensions.
The Cortex-M7 core has a 6-stage integer pipeline delivering high performance of up to 300 MHz operation frequency. It uses an enhanced Thumb instruction set with extra 16- and 32-bit instructions for improved performance, code density and efficiency.
The core microarchitecture incorporates multiple low-latency memory interfaces including separate instruction and data TCM interfaces for deterministic real-time response. It has a hardware multiply instruction and optional DSP extension instructions to accelerate signal processing and control algorithms.
The Cortex-M7 has branch prediction and return stack techniques to improve performance together with low-latency interrupt handling for fast exception response times.
The Cortex-M7 processor incorporates Tightly Coupled Memories (TCM) for fast low-latency access to code and data. This includes 64KB instruction TCM and 64KB data TCM interfaces.
For system memory, the core uses the AMBA AHB-Lite bus protocol which can be configured with multiple bus masters. It has optional MPU and cache support allowing implementation in cache coherent multi-core systems.
The optional MPU provides memory protection and accelerates context switching in advanced RTOSes. The processor also includes optional ECC logic for safety-critical applications requiring high reliability.
DSP and FPU
The Cortex-M7 optionally includes a single precision floating point unit (FPU) for accelerated floating point math performance. This is useful for applications involving complex math, matrix operations, filters or transforms.
The optional FPU provides full IEEE 754 compliance with high efficiency hardware assists for common transcendental functions. It can perform single-cycle floating point multiply-accumulate (MAC) operations.
The Cortex-M7 can also be configured with a double precision FPU for applications requiring 64-bit precision. Additional DSP instructions are included to accelerate DSP algorithms and digital control systems.
Debug and Trace
The Cortex-M7 contains embedded trace and debug features for Real-time system and application debugging. This includes 4-pin trace port supporting trace capture using Embedded Trace Macrocell (ETM) or Micro Trace Buffer (MTB).
ETM provides instruction and data tracing with minimal CPU overhead. MTB captures trace in on-chip memory for export via the debug interface. The embedded debug module provides breakpoint, watchpoint and system profiling capabilities.
The processor includes advanced power saving techniques to enable energy-efficient operation. This includes multiple low power modes with fast wake-up times to minimize power consumption.
The Cortex-M7 supports dynamic voltage and frequency scaling to match CPU performance to application requirements. Clock gating and power gating techniques reduce dynamic and static power dissipation when not actively in use.
For secure applications, the Cortex-M7 can be configured with Arm TrustZone extensions. This provides secure and non-secure states to protect trusted software and data resources from unauthorized access.
Optional cryptographic extensions support encryption, decryption, hashing and authentication using AES, SHA-1, SHA-256 algorithms. True random number generation and CRC calculation accelerators are also included.
Licensing and Silicon Implementation
The Cortex-M7 is designed by Arm and licensed to silicon partners for integration into system-on-chip (SoC) products. It is implemented on advanced process technologies down to 28nm and lower geometries.
The Cortex-M7 has been licensed and deployed in a wide range of embedded applications including automotive systems, industrial automation, robotics, wireless infrastructure, home appliances and consumer electronics.
Leading semiconductor companies that have licensed and implemented the Cortex-M7 in silicon include NXP, STMicroelectronics, Infineon, Silicon Labs, Cypress, Microchip, Renesas, Nuvoton and XMOS.
In summary, the Cortex-M7 provides high performance 32-bit processing for demanding embedded applications. With features like a 6-stage pipeline, optional DSP/FPU, debug/trace, and power management, it enables developers to meet requirements for advanced real-time systems.