Generated by Foxit PDF Creator Foxit Software ttp//www.foxitsoftware.comForevaluationonly 第5章数字集成电路基本模块 53时序单元电路
1 第5章 数字集成电路基本模块 5.3 时序单元电路 Generated by Foxit PDF Creator © Foxit Software http://www.foxitsoftware.com For evaluation only
Generated by Foxit PDF Creator Foxit Soft ttp//www.foxitsoftware.comForevaluation 时序单元电路 ■时序逻辑 双稳态电路 RS锁存器/触发器 D锁存器/触发器 动态时序单元
2 时序单元电路 时序逻辑 双稳态电路 RS锁存器/触发器 D锁存器/触发器 动态时序单元 Generated by Foxit PDF Creator © Foxit Software http://www.foxitsoftware.com For evaluation only
Generated by Foxit PDF Creator Foxit Soft ttp//www.foxitsoftware.comForevaluation 时序逻辑电路 ■肘序逻辑电路的输出不仅与当前的输入变量有关,还与糸 统原来的状态有关,必须有存储部件用来记忆电路前一时 刻的工作状态 组合逻辑 存储元件 输出方程 Y(n)=f(X(n),Z() 状态方程 Z(n+1)=f1(X(m)2Z(m)
3 时序逻辑电路 时序逻辑电路的输出不仅与当前的输入变量有关,还与系 统原来的状态有关,必须有存储部件用来记忆电路前一时 刻的工作状态 输出方程 状态方程 Y n f X n Z n ( ) ( ), ( ) 1 2 Z n f X n Z n ( 1) ( ), ( ) Generated by Foxit PDF Creator © Foxit Software http://www.foxitsoftware.com For evaluation only
Generated by Foxit PDF Creator Foxit Soft ttp//www.foxitsoftware.comForevaluation 时序特性 clock clock time su hold dafa stable time Out output output stable stable time
4 时序特性 clock In Out data stable output stable output stable time time time clock tsu thold tc-q Generated by Foxit PDF Creator © Foxit Software http://www.foxitsoftware.com For evaluation only
Generated by Foxit PDF Creator Foxit Soft ttp//www.foxitsoftware.comForevaluation System Timing constraints Inputs Outputs Combinational Logic Current Next State State clock T(clock period) + t 十 5
5 System Timing Constraints Combinational Logic clock Outputs Next State Current State Inputs T tc-q + tplogic + tsu T (clock period) Generated by Foxit PDF Creator © Foxit Software http://www.foxitsoftware.com For evaluation only