Cortex-M3与Cortex-M4之间的差

The ARM Cortex-M4 processor is the latest embedded processor by ARM specifically developed to address digital signal control markets that demand an efficient, easy-to-use blend of control and signal processing capabilities in microcontroller applications. The combination of high-efficiency signal processing functionality with the low-power, low cost and ease-of-use benefits of the Cortex-M family of processors is designed to satisfy the emerging category of flexible solutions specifically targeting the motor control, automotive, power management, embedded audio and industrial automation markets. The Cortex-M4 processor extends the use of Cortex-M cores to applications that require more computational performance than available currently with Cortex-M3. The Cortex-M4 features a single-cycle multiply-accumulate (MAC) unit, optimized single instruction multiple data (SIMD) instructions, saturating arithmetic instructions and an optional single precision Floating-Point Unit (FPU). So, the Cortex-M4 is a Cortex-M3 with the DSP instruction add-ons, and migrating from Cortex-M3 to Cortex-M4 is very easy!