自主MCU外设提供嵌入式设计，具有许多功能。

　　自主MCU外设提供嵌入式设计，具有许多功能。

　　从微处理器的主处理器中卸下许多常规任务的自治外围内核，在提高嵌入式处理器实时性的同时，也大大降低了能耗。目前可供选择的几种流行的MCU架构的变种，这些所谓的“智能设备”是专用的硬件元素，可以单独或与其它核来完成复杂的数据采集，I / O，和管家功能，CPU处于低功耗的睡眠模式。除了巨大的功率节省之外，这些智能外设提供了对实时事件的确定性响应，而不需要复杂的中断服务例程或RTOS软件。在本文中，我们将介绍能源微（图1）和Atmel最近推出的智能外设系统的体系结构细节，它们的8位和32位平台以及它们在实际应用中提供的一些优势。

　　Figure 1： This cargo container monitor relies on the autonomous peripherals in Energy Micro’s EFM32 MCU to help it provide shippers with location and status data for a year or more on a single set of batteries. The monitor mounts on a standard shipping container’s main door and uses the EFM32’s compliment of autonomous peripherals to handle routine data collection （GPS coordinates， temperature， shock/vibration， door openings， and tamper detection） while the CPU spends nearly all of its time in a low-power sleep state. （Courtesy of Starcom Systems.）

　　Intelligent evolution

　　Intelligent peripherals are a natural extension of the I/O controllers， algorithmic accelerators， and other specialized hardware modules already used in many MCUs. Today， even many low-cost 8-bit microcontrollers such as Microchip Technology’s PIC18 or STMicro’s STM8 family include specialized state machines or accelerator cores， which offload tasks such as matrix operations， encryption， error correction， or controlling a touch screen. Nevertheless， the accelerator modules， screen controllers， and other I/Os all rely on the main processor （CPU） for one or more aspect of their operation， and often compete with it for access to the memory bus and other shared resources. In contrast， autonomous peripherals only require the CPU when they are being initialized and configured to perform a particular set of functions and， in most cases， communicate using a separate bus.