What is the difference between ARM Cortex-M3 and M4?

The Cortex-M3 and Cortex-M4 are very similar cores. Each offers a performance of 1.25 DMIPS/MHz with a 3-stage pipeline, multiple 32-bit busses, clock speeds up to 200 MHz and very efficient debug options. The significant difference is the Cortex-M4 core’s capability for DSP. Otherwise, the Cortex-M3 will do the job.

What is the difference between Cortex M0 and M4?

The ARM Cortex-M4 with its SIMD and floating-point capabilities ran the tests 12 to 174 times faster than the ARM Cortex-M0 core and consumed 2x to 9x more power. Consequently, the ARM Cortex-M4 core proved to be more energy efficient than the ARM Cortex-M0 core.

How to distinguish between Cortex-M3 and M4 architecture?

Distinguish between Cortex-M3 and M4 architecture and explain briefly the interrupt structure of M3 architecture. Cortex M4 also provides instruction sets of ARM 32 bit type, Thumb 16 bit and Thumb 2. But it also includes range of saturating and SIMD instructions specifically optimized to handle DSP algorithms.

What kind of instructions does the Cortex-M0 have?

The Cortex-M0 / M0+ / M1 include a minor subset of Thumb-2 instructions (BL, DMB, DSB, ISB, MRS, MSR). The Cortex-M3 / M4 / M7 / M33 / M35P have all base Thumb-1 and Thumb-2 instructions. The Cortex-M3 adds three Thumb-1 instructions, all Thumb-2 instructions, hardware integer divide, and saturation arithmetic instructions.

What are the multiply and divide instructions in Cortex-M4?

The Cortex-M4 / M7 (optionally M33 / M35P) include DSP instructions for (16bit × 16bit = 32bit), (32bit × 16bit = upper 32bit), (32bit × 32bit = upper 32bit) multiplications. Note: The number of cycles to complete multiply and divide instructions vary across ARM Cortex-M core designs.

Why are Cortex-M cores not included in legacy cores?

The ARM architecture for ARM Cortex-M series removed some features from older legacy cores: The 32-bit ARM instruction set is not included in Cortex-M cores. Endianness is chosen at silicon implementation in Cortex-M cores. Legacy cores allowed “on-the-fly” changing of the data endian mode.