--- title: VLSI 2 --- # VLSI Computer-Aided Design for VLSI Design NTNU VLSI 電腦輔助設計 <style> .caption{ color:grey; font-size:2px; } </style> ##### [Back to Note Overview](https://reurl.cc/XXeYaE) ##### [Back to VLSI Computer-Aided Design for VLSI Design](https://hackmd.io/@NTNUCSIE112/VLSI110-1) {%hackmd @sophie8909/pink_theme %} ###### tags: `VLSI` `110-1` `CSIE` `選修` `NTNU` <!-- tag順序 [學校] [系 必選] or [學程 學程名(不含學程的 e.g. 大師創業)] [課程] [開課學期]--> <!-- 網址名稱 VLSI110-1_[] --> ## Ch2. VHDL-Basic Elements and Dataflow ### Identifiers and Data Objects #### Iderntifiers #### Data Objects - holds a value of a specified type - created bt means of an object declaration ![](https://i.imgur.com/R3BZAGf.png) - Every data object belongs to one of the following four classes 1. Constant - declaration - simple example - `constant BUS_WIDTH: INTER :=8;` 2. Varible - declaration - simple example - `varibale FOUND, DOWN: BOOLEAN;` 3. Signal - declaration - simple example ```vhdl= signal CLOCK: BIT; signal DATA_BUS: BIT_VECTOR(0 to 7); signal INIT_P: STD_LOGIC_VECTOR(7 downto 0); ``` 4. File ### Data Types of VHDL <!-- 縮起來好打 --> 1. Scalar Types - Enumeration - BOOLEAN (FALSE, TRUE) - BIT ('0', '1') - STD_LOGIC - not default, need `STD_LOGIC_1164` package - values | value | explain | | | ----- | --------------- | --- | | 'U' | Un-Initialed | | | 'X' | Forcing Unknown | | | '0' | Forcing 0 | | | '1' | Forcing 1 | | | 'Z' | High Impedance | | | 'W' | Week Unknown | | | 'L' | Week Low | | | 'H' | Week High | | | '-' | Don't Care | | - Integer - range: (0, 15), 4 bits - Physical <font class="caption">不常用</font> - Floating <font class="caption">不常用，高階語言的 floating 是由硬體算出來的所以在硬體這邊這堂課先不討論。</font> 2. Composite Types - Array ```vhdl= type ADDRESS_WORD is arr ``` ![](https://i.imgur.com/RRmo1J6.png) - BIT_VECTOR - STRING - STD_LOGIC_VECTOR - Record <font class="caption">不常用</font> 3. Access Types 4. File Types <!-- 1015 大概講到 ARRAYhttps://moodle3.ntnu.edu.tw/ --> - Difference between downto and to - 沒聽清楚他說啥，但結論是建議用 downto - 因為多數工程師用 downto，若你用 to 合併可能會出問題 ### Operators and Attributes The predefined operators in the language are classified into the following 6 categories: 1. Logical operators 2. Relational operators 3. Shift operators 4. Adding operators 5. Multiplying operators 6. Miscellaneous operators ### Dataflow Model ### Entity Declaration and Architecture Body ### Concurrent Signal Assignment ### Conditional Signal Assignment ### Selected Signal Assignment