HY120 ??F???? S?????S?

1
HY120 ??F???? S?????S?

• S??d?ast??a ?????µata µe
• MSI ?a? LSI

2
S?ed?as? s??d?ast???? ?????µat??

• Sta p??????µe?a e?daµe t?? t??p? s?ed?as?? ?a?
  a?a??s?? ??????? ?????µat?? µe ap?e? p??e? p??
  ß??s???ta? µesa se SSI ICs.
• Ta as???????µe t??a µe t?? s?ed?as? ?????µat??
  ???s?µ?p????ta? p?? s???eta ?p?s?st?µata ta ?p??a
  ?pa????? se µ??f? MSI ? LSI IC.
• S?ed?as? µe eµp????a d?a?es?µa chips ?a? p??????a
  µe??d??
• S?ed?as? µe ???s? ap???d???p???t??, p???p?e?t??,
  ROMs, PLDs ?.?.p.

3
?a?a?????? ??ad???? ?????st??

• ??daµe p?? s?ed?a?eta? ? ?µ?-a????st?? ?a? ?
  p????? a????st??.
• Ta s?ed?as??µe t??a e?a? pa?a????? a????st? 4-bit
  a???µ??.
• ?a?ade??µa ?1011, ?0011 gt S1110 ?a? C0
• ?e??t?? i 4 3
  2 1
• ??at??µe?? e?s?d?? 0 1 1 0
  Ci
• ?
  1 0 1 1 Ai
• ?
  0 0 1 1 Bi
• ?????sµa 0 1 1 1 0
  Si
• ??at??µe?? e??d?? 0 0 1 1
  Ci1

B1 A1
B2 A2
B3 A3
B4 A4
C5
C1
C2
C3
C4
Full Adder
Full Adder
Full Adder
Full Adder
S1
S2
S3
S4
4
?a?a?????? ??ad???? ?????st?? (2)

• H "??ass???" s?ed?as? ?a apa?t??se p??a?a
  a???e?a? µe 2441512 ??aµµe? ?a? 41 st??e?.
• ?? 74283 e??a? e?a ????????µe?? t?? ?????e?e?a?
  TTL p?? pe??e?e? e?a? 4 bit a????st?
• 
  EF????G? BCD se Excess-3

C5
5V
0
74283
? 4
BCD
74283
? 4
4
4 S
S
4
B4
1 1 0 0
C1
A1 A2 A3 A4
? 4
B1

0
5
?a??ste??se?? st?? pa?a????? d?ad??? a????st?

?4 ?4 ?3 ?3 ?2 ?2
?1 ?1
C2
C3
C4
C1
C5
S4 S3 S2
S1
?e??st? ?a??ste??s? ap? t? C1 st? C5. ?s? µe
2x419 ?a??ste??se?? p????
?pe?d? ??e? ?? p?a?e?? ?????ta? µe t?? ß???e?a
t?? p??s?es?? e??a? s?µa?t??? ?a e?att??e? ?
?????? d?ad?s?? t?? ??at??µe???.
6
??ad?s? ??at??µe???

• ?p? t? d?a??aµµa t?? p?????? a????st? ß?ep??µe
  ?t?
• PiAi?Bi, GiAiBi, SiPi ?Ci ?a?
• Ci1GiPiCi
• ?a Gi ?a? Pi eµfa?????ta? µe
• ?a??ste??s? µ?a? p????.
• G?a ?a?e ßa?µ?da ??af??µe t? ??at??µe?? e??d??
  sa? a????sµa ????µe??? (2ep?ped? ???p???s?)
  µetaß??t?? p?? ?p????????ta? µe ?a??ste??s? µ?a?
  p????
• C1C1,
• C2G1P1C1,
• C3G2P2C2G2P2(G1P1C1)G2P2G1P2P1C1
• C4G3P3C3G3P3(G2P2G1P2P1C1)G3P3G2P3P2G1P3
  P2P1C1
• C5G4P4C4G4P4G3P4P3G2P4P3P2G1P4P3P2P1C1

7
??ad?s? ??at??µe???

• ?atas?e?a???µe e?a ?????µa µe e?s?d??? ta C1, G1,
  P1,,G4, P4 ?a? e??d??? ta C2, C3, C4 ?a? C5
  s?µf??a µe t?? p??????µe?e? s?ese??. St? ?????µa
  a?t? s??de??µe t?? e?s?d??? ?a? e??d??? t??
  pa?a?????? a????st? ?p?? st? s??µa.

?????µa p??ß?e??? ??at??µe??? (2 ep?peda ???????)
C1
S??????? ?a??ste??s? 121 4 ?a??ste??se?? p????
C5
8
?e?ad???? ?????st??

• Te???µe ?a s?ed?as??µe e?a ?????µa t? ?p??? ?a
  ß??s?e? t? a????sµa d?? a???µ?? se µ??f? BCD (
  e?a ??at??µe?? e?s?d??)
• ?e "??ass???" s?ed?as? ??e?a??µaste p??a?a
  a???e?a? µe 2441512 ??aµµe? ?a? 2x48 st??e?.
• ??a??a?t??a µp????µe ?a ???s?µ?p???s??µe e?a? 4
  bit d?ad??? pa?a????? a????st? t?? ?p??? ?a
  t??f?d?t?s??µe µe t??? d?? 4 bit BCD a???µ???. ?
  e??d?? t?? a????st? ?a e??a? e?a? d?ad????
  a???µ?? µeta?? 0 ?a? (991) 19, t?? ?p??? ?a
  p?epe? ?a µetat?e???µe se a???µ? BCD.

BCD ?
A
B
C1
4 bit a????st??
S
C5
Binary to BCD
BCD
???ade?
?e?ade?
9
?etat??pea? Binary to BCD
BCD?
?
?

• C5 S4 S3 S2 S1 ? ?4 ?3 ?2 ?1 Binary
• 0 0 0 0 0 0 0 0 0 0 0 0
• 1 0 0 0 0 1 0 0 0 0 1
  1
• 2 0 0 0 1 0 0 0 0 1 0
  2
• 3 0 0 0 1 1 0 0 0 1 1
  3
• 4 0 0 1 0 0 0 0 1 0 0
  4
• 5 0 0 1 0 1 0 0 1 0 1
  5
• 6 0 0 1 1 0 0 0 1 1 0
  6
• 7 0 0 1 1 1 0 0 1 1 1
  7
• 8 0 1 0 0 0 0 1 0 0 0
  8
• 9 0 1 0 0 1 0 1 0 0 1
  9
• 10 0 1 0 1 0 1 0 0 0 0
  16 (106)
• 11 0 1 0 1 1 1 0 0 0 1
  17 (116)
• 12 0 1 1 0 0 1 0 0 1 0
  18
• 13 0 1 1 0 1 1 0 0 1 1
  19
• 14 0 1 1 1 0 1 0 1 0 0
  20 (146)
• 15 0 1 1 1 1 1 0 1 0 1
  21
• 16 1 0 0 0 0 1 0 1 1 0
  22
• 17 1 0 0 0 1 1 0 1 1 1
  23

C5
C1
4 bit d?ad???? a????st??
0
S2
S4
S3
S1
0
0 ? 6
C1
4 bit d?ad???? a????st??
0
? ?4 ?3 ?1 ?0
10
?p??p???µe??? ?etat??pea? Binary to BCD
BCD A B
C5
C1
4 bit d?ad???? a????st??
0
S2
S4
S3
S1
?a ap?de??ete ?t? t? ?????µa e??a? s?st?
C3
C1
2 bit d?ad???? a????st??
0
? ?4
?3 ?2 ?1
11
S?????t?? µe?e???? a???µ??

• ?a s?ed?as?e? e?a ?????µa t? ?p??? s??????e? d??
  a???µ??? ? ?a? ? t?? 4 bits ?a? e?e???p??e? µ?a
  ap? t?? t?e?? e??d??? t?? p?? a?t?st?????? st??
  t?e?? pe??pt?se?? ?gt?, ?? ?a? ?lt?.
• ?e t?? "??ass???" µe??d? ??e?a?eta? p??a?a?
  a???e?a? µe 244256 ??aµµe? ?a? 3 st??e?.
• G?a ap??p???s? t?? d?ad??as?a? efa?µ????µe µ?a
  te????? s?????s?? pa??µ??a µe a?t? p??
  ???s?µ?p??e? ? a????p?? ?a? ?a s??????e? d??
  a???µ???
• ?st?sa? d?? 4 bit a???µ?? ??3?2?1?0 ?a?
  ??3?2?1?0.
• ???fa??? ?? ? ?3?3, ?2?2, ?1?1, ?a?
  ?0?0.
• ?? xk ?k??k AkBkAk'Bk' t?te xk1 a? ?k?k ?a?
• ?? ? xk1,?k?x3x2x1x0
• ??a, a? (??) e??a? ? ?????? µetaß??t? p??
  ???eta? 1 a? ??, t?te (??) x3x2x1x0

12
S?????t?? µe?e???? a???µ?? (s??e?e?a)

• G?a ?a ß???µe t?? s?es? t?? ? ?a? ? s????????µe
  d?ad????a ta ??f?a t??? a??????ta? ap? ta
  pe??ss?te?? s?µa?t??a

(??) x3x2x1x0
?3, ?3
?3lt?3
?3gt?3
?3?3
(?gt?)?3?3'x3A2B2'
x3x2A1B1'x3x2x1A0B0'
?2, ?2
?2lt?2
?2gt?2
?2?2
(?lt?)?3'?3 x3A2'B2
x3x2A1'B1x3x2x1A0'B0
?1, ?1
?1lt?1
?1gt?1
?1?1
A 4
S?????t?? µe?e???? 74LS85
AgtB
?0, ?0
?0gt?0
?0lt?0
AB
B 4
?0?0
AltB
??
?gt?
?lt?
AgtB AB AltB
13
?p???d???p???t?? - Decoder

• ? ap???d???p???t?? ap? n se m ? 2n e??a? e?a
  ?????µa µe n e?s?d??? ?a? m e??d???. ??a???a µe
  t?? s??d?asµ? d?ad???? t?µ?? st?? e?s?d??? t??
  e?e???p??e?ta? µ?a ?a? µ??? e??d??
• ? ap???d???p???t?? pa?a?e? t??? m ? 2n
  e?a??st????? t?? n µetaß??t??.
• ?a?ade??µa Decoder 3 se 8

n
?p???d???p???t?? Decoder

x y z
D0
74138

x' y' z'
D7
D0
x y z D0 D1 D2 D3 D4 D5 D6 D7 0 0 0
1 0 0 0 0 0 0 0 0 0 1 0
1 0 0 0 0 0 0 0 1 0 0
0 1 0 0 0 0 0 0 1 1 0
0 0 1 0 0 0 0 1 0 0 0 0
0 0 1 0 0 0 1 0 1 0 0
0 0 0 1 0 0 1 1 0 0 0
0 0 0 0 1 0 1 1 1 0 0 0
0 0 0 0 1
x' y' z'
D1
.
x y z
D7
14
?p???d???p???t?? BCD - BCD Decoder

• ?a s?ed?as?e? e?a ?????µa t? ?p??? ?ta? st?? 4
  e?s?d??? t?? efa?µ??eta? e?a? a???µ?? BCD
  e?e???p??e? µ?a ap? t?? 10 e??d??? t??. ???a?
  d?a?es?µ? st? eµp???? µe a???µ? se??a? TTL 7442.

w x y z
?a?????a ??e?a???ta? 10 ?a?te? Karnaugh ??a t??
s?ed?as?.
D0
BCD se de?ad???
D1
D9
?p????µe ?a ap??p???s??µe t?? d?ad??as?a a? a?t?
1 ??a???µe Di st?? ?a?t? Karnaugh. ?pa????? 6
ad?af???? ????
yz 00 01 11 10
?? s?µßa??e? ?ta? st?? e?s?d??? efa?µ?s?e?
ad?af??? e?s?d??? St? 7442 ??e? ??
e??d?? ?????ta? 1
D0w'x'y'z', D1w'x'y'z, D2w'x'yz', D9 wz
wx 00 01 11 10
D0 D1 D3 D2
D4 D5 D7 D6
X X X X
X X
D8 D9
15
???p???s? s??d?ast???? ???????

• ??a? ap???d???p???t?? n se 2n eµfa???e? st??
  e??d??? t?? ????? t??? e?a??st????? t?? n
  µetaß??t??.
• ?a?e s??a?t?s? Boole e??a? a????sµa t??
  e?a??st???? t??.
• ?ata s??epe?a ?a?e s??a?t?s? Boole t?? n
  µetaß??t?? µp??e? ?a ???p????e? µe e?a?
  ap???d???p???t? n se 2n ?a? µ?a p??? OR p?????
  e?s?d??.
• ?a?ade??µa ???p???s? p?????? a????st?.

x y z
SS(1,2,4,7) CS(3,5,6,7)
FA
S
0 1 2 3 4 5 6 7
?p???d???p???t?? 3 se 8
x y z
C
16
?p?p?e?te? - Demultiplexers (DeMuxs)

• ? ap?p?e?t?? e??a? e?a ?????µa p?? de?eta?
  ded?µe?a se µ?a ??aµµ? e?s?d?? ?a? ta µetaß?ßa?e?
  se µ?a ap? t?? 2n ??aµµe? e??d?? s?µf??a µe t??
  t?µe? t?? n µetaß??t?? st?? e?s?d??? e?e????.
• ???p???s? ap?p?e?t? 1?4
• ???a?a? a???e?a?
• ? x y D0 D1 D2 D3
• 0 XX 0 0 0 0
• 1 0 0 1 0 0 0
• 1 0 1 0 1 0 0
• 1 1 0 0 0 1 0
• 1 1 1 0 0 0 1

xy

D0 D1 D2 D3
D0 D1 D2 D3
00 01 10 11
1?4 Demux
E E?s?d??

E
?


x y
x y
xy 00 01 10 11
D0 D1 D2 D3
E
Decoder
x y
17
?p?p?e?t?? ?p???d???p???t?? µe e?s?d?
ep?t?e??? (Enable)

• ?p? t? p??????µe?? slide p????pte? ?t?
• ?ta? ?0 ? ap???d???p???t?? e?e? 0 se ??e? t??
  e??d???. ?ta? ?1 e??a?eta? ?a?????a. ? e?s?d??
  E(nable) µa? ep?t?epe? ?a s???et??µe
  p???p????te???? ap???d???p???te?

• ? x y D0 D1 D2 D3
• 0 XX 0 0 0 0
• 1 0 0 1 0 0 0
• 1 0 1 0 1 0 0
• 1 1 0 0 0 1 0
• 1 1 1 0 0 0 1

D0 D1 D2 D3
D0 D1 D2 D3
x y
2 se 4 Decoder µe Enable
?
1X4 Demux
?
x y
E
D0 D3 D4 D7
x y z
2 se 4 Decoder
3 se 8 decoder
D0 D3 D7
x y z
?
2 se 4 Decoder
18
??d???p???te? - Encoders

• O ??d???p???t?? e?te?e? t?? a?t?st??f? ?e?t?????a
  ap? t?? ap???d???p???t?.
• 
  ??e???p??e?ta? µ?a µ??? e?s?d?? ?a?e
• 
  f??a ?a? st?? e??d? eµfa???eta? ?
  
  ??d???? a???µ?? t?? e?e???p???µe???
• 
  e?s?d??.
• ?a?ade??µa S?ed?as? ??d???p???t? 8 se 3
• D0 D1 D2 D3 D4 D5 D6 D7 x y z
• 1 0 0 0 0 0 0 0 0 0 0
• 0 1 0 0 0 0 0 0 0 0 1
• 0 0 1 0 0 0 0 0 0 1 0
• 0 0 0 1 0 0 0 0 0 1 1
• 0 0 0 0 1 0 0 0 1 0 0
• 0 0 0 0 0 1 0 0 1 0 1
• 0 0 0 0 0 0 1 0 1 1 0
• 0 0 0 0 0 0 0 1 1 1 1

n
2n
2n se n encoder
??ep??µe ?t? ? D0 de? s??deeta? p???e?a.
?ta? e??a? D01 ?a? Di0 ta xyz000, a??a t? ?d??
s?µßa??e? ?ta? ??a ta Di0
x D4D5D6D7 y D2D3D6D7 z D1D3D5D7
?? p??ß??µa ???eta? µe µ?a ep?p?e?? e??d? ? ?p??a
???eta? 0 a? ? e?s?d?? de? e??a? e????? ( µ?a
µ??? ?s? µe e?a)
19
??d???p???t?? p??te?a??t?ta? Priority encoder

• ? ??d???p???t?? p??te?a??t?ta? e??a? e?a?
  ??d???p???t?? t?? ?p???? ?? e?s?d?? ?atatass??ta?
  ?ata p??te?a??t?ta.
• ??e???p??e?ta? ?a?e f??a e?e??? ? e??d?? t??
  ?p??a? ? ??d???? a?t?st???e? st?? e?s?d? µe t??
  µe?a??te?? p??te?a??t?ta p?? e??a? se ?atastas?
  1.
• S?ed?as? ??d???p???t? p??te?a??t?ta? 4 se 2

H ep?p?e?? e??d?? z ???eta? 1 a? ??e? ?? e?s?d??
e??a? 0. ???ad? zI0I1I2I3
?0 ?1 ?2 ?3
y1 y2 z
Priority encoder
?0?1 00 01 11 10
?0?1 00 01 11 10
?2?3 00 01 11 10
?2?3 00 01 11 10
gt gt gt
I0 I1 I2 I3 y1 y2 z 0 0 0 0 X X
0 1 X X X 0 0 1 0 1 X X 0 1 1 0
0 1 X 1 0 1 0 0 0 1 1 1 1
0 0 0 0 0 0 0 0
? 1
0 0 0 0
0 0 0 0 0 0 0 0
? 1
1 1 1 1
1 1
0 0
y1 I0'I1'
y2 I0'I1 I0'I1'
20
????p?e?te? - Multiplexers

• ????p?e??a µetaß?ßas? µe?a??? a???µ?? ded?µe???
  µesa ap? µ????te?? a???µ? ?a?a???? ? ??aµµ??.
• ????p?e?t?? ?????µa p?? ep??e?e? p????f???e?
  a?aµesa se p???e? ??aµµe? e?s?d?? ?a? t??
  ?ate????e? se µ?a e??d?. ? ep????? ???eta? µes?
  ??aµµ?? ep??????.
• ?a?ade??µa ????p?e?t?? 4x1

Decoder
I0 I1 I2 I3
I0
00 01 10 11
4x1

Y I0s0's1'I1s0s1'I2s1s2'I3s1s0
I1
Y
s1 s0
I2
s1 s0 Y 0 0 I0 0 1 I1 1 0 I2 1 1
I3
I0 I1 I2 I3
I0 I1 I2 I3
Y
I3
s1
s1 s0
s0
21
????p?e?te? - Multiplexers

• O ????p?e?t?? 2n se 1 ???p??e?ta? µe e?a?
  ap???d???p???t? ap? n se 2n ??aµµe?, st?? p??e?
  AND t?? ?p???? e???? p??ste?e? 2n ??aµµe?
  e?s?d??, µ?a se ?a?e p???. ?? e??d?? t?? p????
  ??D s??de??ta? se µ?a p??? OR t?? 2n e?s?d??.
• ?? µe?e??? d?deta? sa? 2nx1 ?a? p???p??ete? t??
  ?pa??? n ??aµµ?? ep??????.
• S???a ?? p???p?e?te? e???? ?a? µ?a e?s?d?
  ep?t?e??? (enable)
• ?ta? ? e?s?d?? Enable 1 t? ?????µa ?e?t????e?
  ?a?????a , e?? ?ta? Enable0 ?? e??d?? ?????ta?
  0. ??a a??? ???µas?a ??a t?? e?s?d? Enable e??a?
  Strobe.

22
?a?ade??µa ????p?e?t? (74157)

• St? eµp???? d?at??eta? ?p? µ??f? IC e?a?
  tet?ap??? p???p?e?t??
• 2 se 1, µe ????? e?s?d? Enable ?a? ?????
  e?s?d? ep?????? (select).

A1 A2 A3 A4 B1 B2 B3 B4 S E
E 1 gt e?e???p???s? ?????µat?? S 0 gt ep?????
t?? ?, ???? S 1 gt ep????? t?? ?, ????
Y1 Y2 Y3 Y4
? S Yi 0 X 0 1 0 Ai 1 1
Bi
4
4p??? 2 se 1 MUX
A B S E
Y
4
4
E
A B S
0
Y
1
23
???p???s? s??a?t?se?? Boole

• ??daµe ?t? µe e?a? ap???d???p???t? n se 2n ?a?
  µ?a p??? OR 2n e?s?d?? µp????µe ?a pa?ast?s??µe
  µ?a ?p??ad?p?te s??a?t?s? Boole t?? n µetaß??t??.
• ??at?e???ta? st? ?????? d?a??aµµa e??? p???p?e?t?
  2n se 1 ß?ep??µe ?t? pe??e?e? e?a?
  ap???d???p???t? n se 2n ?a? µ?a p??? OR. ??a
  µp??e? ?a ???s?µ?p????e? ??a t?? ???p???s?
  s??a?t?se?? Boole.
• ? ???p???s? ???eta? af?? a?a??s??µe t?? s??a?t?s?
  se a????sµa e?a??st????, efa?µ????ta? e?a 1 ? e?a
  0 st?? e?s?d??? t?? p???p?e?t? a?a???a µe t? a?
  a???e? ? ??? st?? s??a?t?s? ? e?a??st???? p??
  a?t?st???e? se ?a?e e?s?d?.
• G?a s??a?t?se?? n µetaß??t?? ??e?a??µaste e?a?
  p???p?e?t? 2n se 1

24
???p???s? s??a?t?se?? Boole (2)

• ?a?ade??µa ?st? ?t? ?e???µe ?a ???p???s??µe t??
  s??a?t?s? zx?yxy'x'y µe e?a? p???p?e?t? 4 se
  1. ??ep??µe ?t? z S(1,2).
• ???a ? ?d?a s??a?t?s? µp??e? ?a ???p????e? ?a? µe
  p???p?e?t? 2x1
• Sta ep?µe?a ?a a?apt????µe s?st?µat??? t??p?
  ???p???s?? s??a?t?se?? Boole t?? n µetaß??t?? µe
  p???p?e?te? 2n-1x1

0 1 1 0
I0 I1 I2 I3
4x1
4x1
4x1
x y
z
z
z
?
?
x y
x y
0 1 1 0
zx'yxy'
2x1
y y'
0 1
x
25
???p???s? s??a?t?se?? Boole (3)

• ?a?ade??µa 1o ?a ???p????e? ? F(x,y,z) S
  (1,3,5,6)
• ?a?ade??µa 2o ?a ???p????e? ? F(w,x,y,z) S
  (0,1,3,4,8,9,15)

0 1 0 1 0 1 1 0
8x1 23x1
0 1 2 3 4 5 6 7
yz 00 01 10 11 x I0
I1 I2 I3 0 0 1 2
3 1 4 5 6 7 0
1 x x'
0 1 x x'
4x1
F
F
y z
x y z
8x1 23x1
0 1 2 3 4 5 6 7
1 1 0 w' w' 0 0 w

• xyz 000 001 010 011 100 101 110 111
• w I0 I1 I2 I3 I4
  I5 I6 I7
• 0 0 1 2 3 4 5
  6 7
• 8 9 10 11 12 13 14
  15
• 1 1 0 w' w' 0
  0 w

F
x y z
26
Read Only Memory (ROM)

• ??daµe ?t? µe e?a? ap???d???p???t? µe n e?s?d???
  ?a? 2n e??d??? µp????µe ?a ???p???s??µe ?????
  t??? e?a??st????? n µetaß??t??.
• ?e p??e? OR, ?at?p??, µp????µe ?a a????s??µe
  ????? t??? ????? p?? ??e?a??µaste ??a ?a
  ???p???s??µe µ?a s???e???µe?? s??a?t?s? Boole.
• ??a µ??µ? "µ??? a?a???s??" (ROM) µe n e?s?d???
  ?a? m e??d??? pe???aµßa?e? e?a?
  ap???d???p???t? ap? n se 2n ?a? m p??e? OR µesa
  st? ?d?? chip.
• ?? ?ata????e? s??dese?? t?? e??d?? t??
  ap???d???p???t? µe t?? p??e? OR ?????ta? µe t??
  d?ad??as?a t?? "p????aµµat?sµ??".
• ???s?µ?p?????ta? ??a p???p???e? s??a?t?se??.
• ?as??a e??a? st???e?a ap????e?s?? ded?µe??? (2n
  ?ese?? t?? m bits)
• ?a ded?µe?a ?a???????ta? ap? t?? ???st? ?a?
  e???af??ta? µe t?? d?ad??as?a t??
  "p????aµµat?sµ??".

27
Read Only Memory (ROM) (2)

• ?? d?? t??p?? ?e???s?? t?? ROMs
• ???p???s? S??a?t?se??
  ?p????e?s? ?ed?µe???

Decoder ap? n se 2n
m
n
ROM 2n x m
n

m
2n
?a?e s??d?asµ?? ap? n bits t?? e?s?d?? ???µa?eta?
d?e????s? (address) ?a?e s??d?asµ?? ap? m
bits t?? e??d?? ???µa?eta? ?e?? µ??µ??
(word) M?a ROM ?a?a?t????eta? ap? t?? a???µ? t??
?e?e?? 2n ?a? ap? t? µe?e??? t??? m p.?. ???µ?
25 x 8 32 x 8 256 bits
??d???? s??desµ??
?????a ?pa????? s??dese?? µeta?? ???? t?? e??d??
t?? ap???d???p???t? ?a? ???? t?? e?s?d?? t??
p???? OR. ?ata t?? p????aµµat?sµ? ?atast?ef??ta?
?? s??dese?? p?? de? ??e?a???ta?. ?a?aµe????
µ??? ?? apa?a?t?te? ??a t?? ???p???s?
µ?a? s??a?t?s??.
28
M?a ROM 25 x 8

• S??d?ast??? ?????µa

ROM 32x8
5 e?s?d??
8 e??d??
0 1 29 30 31
A0 A1 A2 A3 A4
Decoder 5 x 32 (32 AND 5 NOT)
32x8 256 s??desµ?? p????aµµat?sµ??

F1 F2 F8
29
???p???s? s??d?ast???? ???????

• S??d?ast??? ?????µa µe n e?s?d??? ?a? m e??d???
  apa?te? ??a t?? ???p???s? t?? µ?a ROM 2n x m.
• ?atast?ef??µe t??? s??desµ??? p?? a?t?st?????? se
  e?a??st????? p?? de? a?????? st?? s??a?t?s? Fi,
  gt p????aµµat?sµ?? e??d?? Fi.
• ?a?ade??µa ?a ???p????e? µe ROM s??d?ast???
  ?????µa 2 e?s?d?? ?a? d?? e??d?? F1(A1A0)
  S(1,2,3), F2(A1A0) S(0,2).
• A1 A0 F2 F1
• 0 0 1 0
• 0 1 0 1
• 1 0 1 1
• 1 1 0 1

00 01 10 11
A0 A1
Decoder 2 se 4
X
X
X
Address Words ???a?a? ?????aµµat?sµ??
F1 F2
30
???p???s? s??d?ast???? ??????? (2)

• ?a?ade??µa 2? ?a ???p????e? µe ?ata????? ROM
  ?????µa 3 e?s?d?? t? ?p??? ?p??????e? t?
  tet?a???? t?? d?ad???? a???µ?? st?? e?s?d? t??.
• x ?2 ?1 ?0 ?5 ?4 ?3 ?2 ?1 ?0 x2
• 0 0 0 0 0 0 0 0 0 0 0
• 1 0 0 1 0 0 0 0 0 1 1
• 2 0 1 0 0 0 0 1 0 0 4
• 3 0 1 1 0 0 1 0 0 1 9
• 4 1 0 0 0 1 0 0 0 0 16
• 5 1 0 1 0 1 1 0 0 1 25
• 6 1 1 0 1 0 0 1 0 0 36
• 7 1 1 1 1 1 0 0 0 1 49

A2 A1 A0
ROM 23 x 4
0
B5 B4 B3 B2 B1 B0
0 A0
31
??p?? ROM

• Mask Programmable ?????aµµat????ta? st?
  e???stas?? ?ata t?? ?atas?e?? t??? (µe?a?e?
  p?s?t?te?)
• Programmable ROM (PROM) ?????aµµat????ta? st?
  e??ast???? µe ap?a µesa. ?????a e???? se ?a?e
  d?e????s? 0 ? 1.
• Erasable PROM (EPROM) ?????aµµat????ta? µe ap??
  t??p? st? e??ast???? ?a? "sß????ta?" ?ta?
  e?te???? ep? a??et? ??a se ?pe???d? a?t???ß???a
  (UV). ?p????? ?a ?a?a???s?µ?p???????.
• Electrically Erasable PROM (EEPROM)
  ?????aµµat????ta? ?a? sß????ta? µe ??e?t??? ?e?µa.

32
?e?????? ROM

• ROM
• µ??ada ???p???s?? s??d?ast???? ??????? ?????µat??
• µ??ada ap????e?s?? d?ad???? ded?µe???
• ???s?µ?p?????ta? ??a
• ???p???s? p???p????? s??d?ast???? ?????µat??
• µetat??p? ??d????
• e?te?es? a???µ?t???? p?a?e?? (p.?. p??/sµ??,
  tet?a?????? ???a)
• ?pe?????s? ?a?a?t???? st?? ?????
• ???p???s? µ??ad?? e?e???? ??f?a??? s?st?µat??

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