He thong so

Chng 7

Mch Lun L MSI

CO1009 Digital Systems Chng 7: Mch Lun L MSI

2

Ni dung

Mch gii m

Mch m ha

Mch dn knh

Mch phn knh

CO1009 Digital Systems Chng 7: Mch Lun L MSI

3

Mch gii m c s dng khi cn tch cc mt tn hiu

ng xut hoc mt nhm cc ng xut tng ng vi s xy

ra ng thi ca mt nhm cc tn hiu ng nhp

V d: mt tp cc ng nhp biu din mt s nh phn, mch

gii m ch tch cc ng xut c v tr tng ng vi gi tr thp

phn ca gi tr nh phn ca ng nhp.

Decoder

CO1009 Digital Systems Chng 7: Mch Lun L MSI

4

Tuy nhin, c nhiu b gii m trong thc t tch cc tn hiu outputc chn mc thp trong khi cc output khc mc cao

Decoder

CO1009 Digital Systems Chng 7: Mch Lun L MSI

5

Decoder 74LS138

CO1009 Digital Systems Chng 7: Mch Lun L MSI

6

Decoder 7442

CO1009 Digital Systems Chng 7: Mch Lun L MSI

7

Decoder

CO1009 Digital Systems Chng 7: Mch Lun L MSI

8

Decoder BCD to 7-Segment

CO1009 Digital Systems Chng 7: Mch Lun L MSI

9

Decoder BCD to 7-Segment

CO1009 Digital Systems Chng 7: Mch Lun L MSI

10

Thit k mch lun l t hp hin thc mch gii m

BCD thnh n LED 7-on

Bi tp

CO1009 Digital Systems Chng 7: Mch Lun L MSI

11

Most decoders accept an

input code & produce a

HIGH (or LOW) at one

and only one output line.

An encoder has a number of

input lines, only one of

which

is activated at a given time.

A decoder identifies,

recognizes, or detects a

particular code.

Encoder

CO1009 Digital Systems Chng 7: Mch Lun L MSI

12

Encoder 74147

CO1009 Digital Systems Chng 7: Mch Lun L MSI

13

ng dng s dng b

m ha

Encoder

CO1009 Digital Systems Chng 7: Mch Lun L MSI

14

Ti mt thi im, ng xut s c kt ni vi mt

trong N ng nhp c chn gi l qu trnh dn knh.

Tn gi khc ca mch dn knh l mch chn d liu.

Multiplexer (MUX)

CO1009 Digital Systems Chng 7: Mch Lun L MSI

15

V d

MUX

CO1009 Digital Systems Chng 7: Mch Lun L MSI

16

MUX

CO1009 Digital Systems Chng 7: Mch Lun L MSI

17

MUX 74157

CO1009 Digital Systems Chng 7: Mch Lun L MSI

18

Mt mch MUX c th c s dng hin thc mt

hm lun l c m t bng bng s tht hoc biu

thc i s

MUX ng dng

CO1009 Digital Systems Chng 7: Mch Lun L MSI

19

MUX ng dng

CO1009 Digital Systems Chng 7: Mch Lun L MSI

20

MUX ng dng

CO1009 Digital Systems Chng 7: Mch Lun L MSI

21

Mt b DEMUX bao gm 1 ng nhp v N tn ng xut.

Ti mt thi im, ch duy nht mt ng xut s c

chn kt ni vi tn hiu ng nhp.

Demultiplexer (DEMUX)

CO1009 Digital Systems Chng 7: Mch Lun L MSI

22

1-Line-to-8-Line DEMUX

CO1009 Digital Systems Chng 7: Mch Lun L MSI

23

DEMUX

CO1009 Digital Systems Chng 7: Mch Lun L MSI

24

Thit k mch lun l t hp hin thc mch gii m

HEX thnh n LED 7-on

Bi tp

CO1009 Digital Systems Chng 7: Mch Lun L MSI

25

Thit k mch kha s in t vi 3 k s v 10 phm

nhn tng ng 0..9.

Tm hiu IC 74HC85 v thit k b so snh 2 s nh

phn 8-bit.

Bi tp