说明：   介绍一种高分辨率的双路A/D转换器AD7711，能满足双路A/D采样要求。内容包括AD7711的特点， 内部寄存器结构和外部接口，并详细阐述了数据采集系统中AD7711与单片机AT89S8252的接口技术，包 括硬件接口电路和软件程序设计及其注意事项。
(Introduce a two-way high-resolution A/D converter AD7711, can satisfy the dual A/D sampling requirements. Include the characteristics of AD7711, the internal register structure and the external interface, and detailed data acquisition system with the AD7711 single-chip AT89S8252 interface technologies, including hardware interface circuit and software design and its attention to matters of procedure.)