# Digital Design (4th Edition)

This preview shows pages 1–21. Sign up to view the full content.

1 Synchronous Sequential Logic Chapter 5 Partially adapted from Maciej Ciesielski Un. Of Massachusetts

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2
3

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
4
5

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
6
7

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
8
9

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
10
11

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
12 Other Flip Flops s D flip flops requires smallest number of gates. s Thus, they are commonly used s Other flip flops are • JK flip flops • T flip flops
13 Three operations of flip flops s Three operations that can be performed with flip flops are • Set it to 1 • Reset it to 0 • Complement its output s D flip flop can only set and reset s JK has two inputs and can perform all three operations JK flip flop s J input sets to 1 s K input resets to 0 s When both inputs are enabled, output is complemented.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
14 JK flip flop s The function of the D input: D=JQ’+K’Q • When J=1 AND K=0, D=Q’+Q=1 • When J=0 AND K=1, D=0 • When J=1 AND K=1, D=Q’ (complemented) • When J=0 AND K=0, D=Q (unchanged) T (toggle) flip flop s It is a complementing ff. s J and K are tied together (Fig a) • When T=0 (J=K=0), no change • When T=1 (J=K=1), complement s Can be constructed from D ff (Fig b) • When T=0, D=Q (no change) • When T=1, D=Q’ (complement) Q T Q T Q T D + = =
15 Characteristic Tables Q(t) refers to the presents state. Q(t+1) refers to the next state. Characteristic Equations s D flip flop Q(t+1)=D s JK flip flop Q(t+1)=JQ’+K’Q s T flip flop Q T Q T Q T t Q + = = + ) 1 (

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
16
17

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
18
19

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
20 Analysis with JK flip-flops s For D flip-flops, state equation is the same as the input equation. s
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 01/13/2011 for the course CENG 275 taught by Professor Suleymantosun during the Spring '10 term at Ankara Üniversitesi.

### Page1 / 44

Chapter5 - Synchronous Sequential Logic Chapter 5 Partially...

This preview shows document pages 1 - 21. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online