7.12 某一 8086CPU 系统中，采用一片 82C59A 进行中断管理。设定 82C59A 工作在 普通全嵌套方式，发送 EOI 命令结束中断，采用边沿触发方式请求中断，IR0 对应的中断向 量码为 90H。 另外，82C59A 在系统中的 I/O 地址是 300H(A0＝0)和 301H(A0＝1)。请编写 82C59A 的初始化程序段

《中国营养师培训教材》是针对参加培训人员的专用教材，同时也是从事营养、食品专业工作人员的参考教材。它包括：基础营养、食物营养与食品卫生、人群营养、公共营养、营养缺乏与营养过量、疾病营养、营养强化与保健食品以及食品加工与烹饪等8篇。 本教材考虑到我国营养工作的实际需要，增加了“营养强化与保健食品”、“食品加工与烹饪”等篇，内容比一般的营养与食品卫生学教材更丰富、全面，具有较强的实用性。本教材是按照培训营养师的需要编写的，适合于有大专以上教育程度的读者。对于助理营养师的培训，需要对教材内容有选择地进行讲授和阅读。 第一篇 基础营养 第二篇 食物营养与食品卫生 第三篇 人群营养 第四篇 公共营养 第五篇 营养缺乏与营养过量 第六篇 疾病营养 第七篇 营养强化与保健食品 第八篇 食品加工与烹饪

Main Purpose Study an algorithm: – Translating a regular expression into a DFA via NFA

Special Notations for Repetitive Constructs Repetition – A → A  |  (left recursive), and – A →  A |  (right recursive) where  and  are arbitrary strings of terminals and non-terminals, and – In the first rule  does not begin with A and

Symbol table: major inherited attribute and major data structure in a compiler Principal operations: – Insert: store the information provided by name declarations when processing these declarations – Lookup: retrieve the information associated to a name when that name is used in the associated code

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:

Why Compiler Writing machine language-numeric codes is time consuming and tedious

The idea of Recursive-Descent Parsing Viewing the grammar rule for a non-terminal A as a definition for a procedure to recognize an A The right-hand side of the grammar for A specifies the structure of the code for this procedure The Expression Grammar:

A bottom-up parser uses an explicit stack to perform a parse – The parsing stack contains tokens, nonterminals as well as some extra state information – The stack is empty at the beginning of a bottom-up parse, and will contain the start symbol at the end of a successful parse

8.1.1 Three-Address Code 8.1.2 Data Structures for theImplementation of Three-Address Code