Shengshi Leju: showcases eight intelligent system intelligence solutions

To gain a foothold in the Internet of Things (IoT) market, original equipment manufacturers (OEMs) must accelerate the pace of innovation. The application of the Internet of Things has made everything possible. Successful companies will urge their developers to expand and adopt new and more practical ways to use the functions of sensors, monitor different types of data, and control the ecosystem of the entire device.

Internet of Things applications cover a wide range of applications , including wearables, automotive, residential, industrial, and even urban. These applications need to be supported by more energy efficient, innovative, and secure systems. Applications are important to achieve intuitive and easy-to-use software development.

Microcontrollers (MCUs) are at the heart of IoT products, and choosing the right MCU is key to meeting your customers' current and future needs. This article explores the rich capabilities of today's growing embedded MCUs, which accelerate design while enabling innovative applications. In the first part, we will introduce advanced process technology, low-power design techniques, power consumption issues for multi-core systems, communication between multiple cores, serial memory interfaces, and system security.

The Internet of Things market (the fastest growing engine):

Internet of Things technology is constantly changing our daily work and lifestyle, making our lives more economical, convenient, comfortable and intelligent. The Internet of Things market can be broadly divided into two categories: consumer Internet of Things and enterprise Internet of Things.

The consumer Internet of Things includes residential, lifestyle, health and travel. Individual users can increase their productivity, safety and quality of life through these IoT device products. From smart homes to connected cars, the consumer market is preparing for the next wave.

Figure 1: Consumer IoT market segmentation

The corporate Internet of Things has a wide range of coverage, including retail, healthcare, energy, travel, urban, manufacturing and public services. The enterprise IoT segment will transform organizations and communities to create a new era of economic growth. The Internet of Things improves productivity, productivity, and day-to-day operations by connecting data, people, and machines. The Enterprise Internet of Things can also be used as a tool to help companies identify new growth opportunities in untapped areas.

Figure 2: Enterprise IoT Market Segmentation

Process Technology (Size – Very Important): The process technology used to make an MCU is critical to its performance, low power consumption, and cost. IoT applications require efficient active power consumption and low power mode consumption to increase the overall system efficiency. With the continuous advancement of manufacturing technology, the core area of ​​silicon has been shrinking. More MCUs can be fabricated on the same silicon, which reduces the overall cost of the chip, and performance and power consumption are directly affected. The reduction in size reduces the current required to turn each transistor on/off while keeping the clock frequency constant. Therefore, a smaller chip means a higher maximum clock frequency and higher performance at lower power consumption.

For example, the 40nm process technology used to make Cypress Semiconductor PSoC 6 BLE Series MCUs provides a high performance, energy efficient solution for a wide range of IoT applications. The current during deep sleep is only a few microamps, and the RAM data can be completely retained. Other power modes, such as run, sleep, low-power operation, and low-power sleep, enable developers to flexibly optimize system power while maintaining high performance for their applications.

Figure 3: Low-Power MCU Block Diagram for IoT Applications

Power (critical): One of the biggest challenges in designing IoT devices is high energy consumption. Most IoT devices are in real-time online, small size, which means that their battery capacity is very limited. MCU vendors need to consider many factors when optimizing their IoT applications, such as:

Improved process technology

Provides a highly flexible power mode

Power-optimized hardware IP module

Higher integration to reduce component count

Optimize flash frequency

Enable caching

Support a wider range of operating voltages

However, while process technology is shrinking in size, improving performance, improving power consumption and integration, there are also problems with current leakage management, especially in low power modes. To address the challenges of current leakage, MCU vendors have adopted special transistor process technologies such as multi-gate devices, high voltage transistors/logic/circuits, specially designed memory cells, and many other technologies.

Flexible power modes enable developers to schedule independent system activities to optimize overall power consumption. It is a key technology in this area that provides a variety of peripherals that can operate in low-power mode and can be woken up to perform their functions without waking up the CPU. Some MCUs also offer peripherals that can perform special low-power modes of operation with limited functionality (such as lower operating frequency and voltage) to further optimize application power consumption, and even design specific peripherals that optimize power consumption, ie BLE radios Designs that support low-power wireless communication can be used.

Another factor that affects power consumption is non-volatile (NV) memory access, especially MCUs that use firmware (NV memory) to store firmware code. Any optimization of flash access will greatly reduce power consumption, with the goal of minimizing the frequency of flash access. Two common techniques are used here, one of which is to provide a cache. In this way, the actual code memory (flash) does not need to be accessed every execution cycle. Another approach is to increase the amount of data acquired in a single cycle and reduce the frequency of access to the flash by using a wider range of flash accesses.

IoT-based MCUs also offer flexible power systems. The MCU can be powered from multiple sources while supporting a wide supply voltage range. For example, simple IoT applications like fitness trackers can be powered by coin cells, while complex IoT applications such as smart watches need to be powered by a PMIC (Power Management IC). In addition, some MCUs effectively regulate their own power supply through their internal buck converters.

When considering the power mode of the MCU, it is important to go beyond its basic architecture. For example, the standard ARM CPU core supports run, sleep, and deep sleep. Additional power modes are typically added by a specific MCU vendor. For example, Cypress's PSoC 6 BLE MCU can perform six operating power modes including low-power operation, low-power sleep, and sleep.

Figure 4: Power Mode Transition Example for PSoC 6 BLE MCU

Multiprocessor MCUs (accelerating the speed of parallel application tasks): As the functionality of IoT systems grows, so does the complexity, but the actual size is getting smaller. The goal of MCU manufacturers is to improve system performance while minimizing size and power consumption. Multicore MCUs and System-on-Chip (SoC) provide higher performance by integrating more features in a single chip and minimizing chip area. A multicore processor is an MCU or SoC that contains two or more independent cores (or CPUs). These cores are usually integrated on a single chip, and they can also be used as multiple chips in a single package.

Multicore MCUs help deliver high performance and keep small size. A typical IoT design, such as a wearable device, requires multiple MCUs, including: a BLE controller for wireless communication, a Touch MCU for executing the user interface, and a primary MCU to implement the application. The functionality of these three MCUs can be provided by a highly integrated multi-core MCU.

Multicore MCUs offer many other benefits. For example, it can integrate enough resources to enable the CPU to process intensive tasks in parallel, thereby maximizing the efficiency of multitasking. This also allows developers to effectively allocate system events to specific cores to achieve power and performance goals. As another example, in a dual-core wearable design, periodic functions that require less CPU intervention, such as wireless broadcast and touch sensing, can be assigned to a single core. Other "frequent touch" features, such as sensor fusions that require frequent CPU intervention, can be assigned to another core. This partitioning reduces latency when running multiple applications on the system. Efficiency can also be improved by integrating the integration of the protocol stack with the program memory.

Figure 5: IoT Multicore MCU Example

Figure 6 shows a multi-core MCU - Cypress MCU PSoC 6 BLE. The dual-core MCU has two 32-bit ARM Cortex CPUs - Cortex-M4 and Cortex-M0+. Both CPUs are 32-bit processors with a 32-bit data path, registers, and memory interface. The Cortex-M4 is a main CPU designed to achieve short interrupt response times, high code density and high 32-bit throughput while maintaining tight cost and power budgets. The Cortex-M0+ acts as a secondary CPU for network security, physical security and protection. The Cortex CPU executes a subset of the Thumb instruction set and has two modes of operation called thread mode and handler mode. These CPUs enter thread mode when they exit the reset and execute the application software. In order to handle exceptions, the CPU enters the handler mode. When all exception handling is complete, the CPU returns to thread mode.