The embedded development solution provider Langruizhike believes that with the increasingly high requirements for embedded systems , the comprehensive performance of the embedded microprocessor as its core is also being increasingly tested. Now the processing capability of a high-end smartphone Almost on par with laptops from a few years ago. ARM has always developed its own microprocessor core architecture, and then licensed the intellectual property rights of these architectures to various chip manufacturers. The streamlined CPU architecture, efficient processing power and successful business model have made ARM a great success, making It quickly captured the majority of the market for 32-bit embedded microprocessors. Motherboard customization
In order to meet the needs of the market, ARM companies are also stepping up research and development of their latest ARM architecture, the Cortex series is such a product. So let's take a good look at the summary of ARM Cortex series processor knowledge points today.
ARM Cortex series processors
ARM's products after the classic processor ARM11 are named after Cortex, and are divided into three categories: A, R, and M, aiming to provide services for a variety of different markets.
1. Cortex-A: For cutting-edge virtual memory-based operating systems and user applications
2. Cortex-R: for real-time systems
3. Cortex-M: Microcontroller
ARM Cortex series processors - Cortex-A
The ARM Cortex-A family is a family of application processors for complex operating systems and user applications. The Cortex-A series processors support the ARM, Thumb and Thumb-2 instruction sets.
RM's Cortex-A series processors are suitable for applications with high computing requirements, running rich operating systems, and providing interactive media and graphics experiences.
As shown in the figure, the green part is the v7-A architecture, and the blue part is the v8-A architecture. Basically, the green part can support 32 and 64 bits, except for A32, which only supports 32 bits. In each part on the right, for example, the top A15-A73 part that requires high performance is the most efficient, and the next part is the part that pays more attention to the overall efficiency. The middle part is more efficient, and the bottom column The ones are the most efficient and meet the best standards in terms of battery performance.
If you have to give them a sequence, it can be roughly sorted from high to low: Cortex-A73 processor, Cortex-A72 processor, Cortex-A57 processor, Cortex-A53 processor, Cortex-A35 processor, Cortex -A32 processor, Cortex-A17 processor, Cortex-A15 processor, Cortex-A7 processor, Cortex-A9 processor, Cortex-A8 processor, Cortex-A5 processor.
ARM Cortex series processors - Cortex-M
The Cortex-M processor family is more concentrated on the low performance side, but these processors are still very powerful compared to the traditional processors used by many microcontrollers. For example, Cortex-M4 and Cortex-M7 processors are used in many high-performance microcontroller products, and the maximum clock frequency can reach 400Mhz.
Of course, performance isn't the only metric for choosing a processor. In many applications, low power consumption and cost are key selection criteria. Therefore, the Cortex-M processor family includes a variety of products to meet different needs:
Unlike older classic ARM processors (eg, ARM7TDMI, ARM9), Cortex-M processors have a very different architecture. E.g:
-Only supports ARM Thumb instructions, has been extended to support both 16-bit and 32-bit instructions Thumb-2 version
-Built-in nested vectored interrupt control is responsible for interrupt handling, automatic handling of interrupt priority, interrupt masking, interrupt nesting and system exception handling.
- The interrupt handling function can be programmed in standard C language, and the nested interrupt handling mechanism avoids using software to determine which interrupt needs to be processed. At the same time, the interrupt response speed is deterministic and low latency.
- The vector table changed from jump instructions to the starting addresses of interrupt and system exception handlers.
- Changes have also been made to register banks and some programming modes.
These changes meant that much of the assembly code written for classic ARM processors needed to be modified, and older projects needed to be modified and recompiled to migrate to Cortex-M products.
ARM Cortex series processors - Cortex-R
R4: The first embedded real-time processor based on the ARMv7-R system. Dedicated to high-capacity deeply embedded SoC applications such as hard disk drive controllers, wireless baseband processors, consumer mobile MTK platforms, and electronic control units for automotive systems.
R5: Launched in 2010, based on the ARMv7-R architecture, it expands the feature set of the Cortex-R4 processor, supports higher levels of system performance, improves efficiency and reliability, and enhances error management in reliable real-time systems. These system-level features include the high-priority Low-Latency Peripheral Port (LLPP), which is used for fast peripheral reads and writes, and the Accelerator Coherent Port (ACP), which is used to increase efficiency and achieve more reliable high-speed communication with external data sources. Cache coherence.
Based on the 40 nm G process, the Cortex-R5 processor can run at nearly 1 GHz, at which point it delivers 1,500 Dhrystone MIPS of performance. The processor provides a highly flexible and efficient two-cycle local memory interface, allowing SoC designers to minimize system cost and power consumption.
R7: The Cortex-R7 processor is the highest performance Cortex-R series processor. It is the standard for high-performance real-time SoCs. The Cortex-R7 processor is designed for the implementation of advanced chip processes based on 65 nm to 28 nm, and its design focus is on improving energy efficiency, real-time responsiveness, advanced features and simplifying system design. Based on the 40 nm G process, the Cortex-R7 processor can run at frequencies in excess of 1 GHz, where it delivers 2700 Dhrystone MIPS of performance. The processor provides a flexible local memory system supporting Tightly Coupled Memory (TCM) local shared memory and peripheral ports, enabling SoC designers to meet demanding hard real-time requirements within constrained chip resources.