学习要点： •掌握常用D/A转换器、A/D转换器的工作原理 •熟悉D/A转换器、A/D转换器的主要性能指标 •了解ADC、DAC在测控系统中的应用 9.1 D/A转换器 9.1.1 R—2R T型电阻D/A转换器 9.1.2 具有双极性输出的D/A转换器 9.1.3 D/A转换器的主要性能指标 9.1.4 集成D/A转换器 9.2 A/D转换器 9.2.1 A/D转换的基本原理 9.2.2 常见ADC的类型 9.2.3 A/D转换器的重要技术参数 9.2.4 集成A/D转换器 9.3 A/D转换器和D/A转换器在测控系统中的应用

一、AD、DA的实际需求 二、D/A转换 三、A/D转换

7.1 模拟量输入通道 7.2 A/D转换接口技术 7.3 D/A转换接口技术

9.1MCS-51单片机与D/A转换器的接口和应用 9.2MCS-51单片机与A/D转换器的接口和应用

Monopoly While a competitive firm is a price taker, a monopoly firm is a price maker

A stack-based environment will result in a dangling reference when the procedure is exited if a local variable in a procedure can be returned to the caller The simplest example:

7.1模拟量输入通道 7.2A/D转换接口技术 7.3D/A转换接口技术

The memory of a typical computer: A register area; Addressable Random access memory (RAM): A code area; A data area. The code area is fixed prior to execution, and can be visualized as follows:

7.1模拟量输入通道 7.2A/D转换接口技术 7.3D/A转换接口技术

One parse tree only a The role of the grammar a distinguish between syntactically legal and illegal programs a But that's not enough: it must also define a parse tree a the parse tree conveys the meaning of the program What if a string can be parsed with multiple parse trees? a we say the grammar is ambiguous a must fix the grammar(the problem is not in the parser) a Note: often a string can be derived in more than one way D ie, with more than one derivation sequence o this does not mean the grammar is ambiguous