The operationsystem calls these services rather than manipulating hardware directly.
操作系统将调用这些服务，而不是直接地操作硬件。
2
As a software layer between embedded operationsystem and hardware in embedded system, HAL (hardware Abstraction layer) is a key problem of embedded application.
在嵌入式系统中，硬件抽象层作为嵌入式操作系统和硬件之间的软件层次是嵌入式应用的一个关键问题。
3
The hardware and software constructions, the operation of this system and several output voltage waveforms are provided in this paper.