Bµi 2.4: Bé so s¸nh
1. Bé so s¸nh b»ng nhau.
!
Ph©n tÝch yªu cÇu:
"#$%&
"#$'&
1.1 Bé so s¸nh b»ng nhau 1 bit:
(
%
)*
+,-./
%
%
+,-./
%
01+
0
02+
≠
!
B¶ng ch©n lý:
!
Tèi thiÓu hãa:
!
S¬ ®å logic:
#$% #$' 3+
2 2 1 4
2 1 2 5.
1 2 2 5.
1 1 1 4
iiiiiii
bababag
⊕=+=
!
Ph©n tÝch yªu cÇu:
"#$%&
"#$'&
1.2 Bé so s¸nh b»ng nhau 4 bit:
6.789:;0
<
1
2
%=40
<
1
2
>01+;04
>02+;≠4
>*
.?.1)%=&
000
111
222
333
bag
bag
bag
bag
⊕=
⊕=
⊕=
⊕=
3@';04+
<
0
<
)
0
)
1
0
1
)
2
0
2
!
B¶ng ch©n lý:
g
3
g
2
g
1
g
0
G
!
Tèi thiÓu hãa:
2 2 2 2 2
2 2 2 1 2
2 2 1 2 2
2 2 1 1 2
2 1 2 2 2
2 1 2 1 2
2 1 1 2 2
2 1 1 1 2
1 2 2 2 2
1 2 2 1 2
1 2 1 2 2
1 2 1 1 2
1 1 2 2 2
1 1 2 1 2
1 1 1 2 2
1 1 1 1 1
0123
ggggG
⋅⋅⋅=
!
S¬ ®å logic:
<
<
1
1
2
2
<
1
2
>
2. Bé so s¸nh.
.7=
A'BC.
!
Ph©n tÝch yªu cÇu:
"#$%&
"#$'&
2.1 Bé so s¸nh 1 bit:
%
01+
D
01+
E
!
B¶ng ch©n lý:
#$% #$'
3+
2 2 2 2
0
2 1 2 1
E
1 2 1 2
D
1 1 2 2
0
!
Tèi thiÓu hãa:
iii
bal
=
iii
bam
=
!
S¬ ®å logic:
!
Ph©n tÝch yªu cÇu:
"#$%&
"#$'&
2.2 Bé so s¸nh 4 bit:
F.'G.789H8-I$J
'*@)K'*@
G=+8L.+'*@8AHH.
6.789:;0
<
1
2
%=40
<
1
2
5+,-.&
>01+;04)
01+
0
01+;D4)
01+
D
M01+;E4)
01+
E
!
B¶ng ch©n lý:
"4-9NO&
<
1
2
<
1
2
3+
;D4
1 1
1 1 1
1 1 1 1
1 1 1 1 1
"4-9NO&
<
1
2
<
1
2
M 3+
;E4
1 1
1 1 1
1 1 1 1
1 1 1 1 1
!
Tèi thiÓu hãa:
0
<
"
<
"
<
1
"
<
1
2
M0
<
"
<
"
<
1
"
<
1
2
!
Tèi thiÓu hãa:
0
<
"
<
"
<
1
"
<
1
2
M0
<
"
<
"
<
1
"
<
1
2
!
S¬ ®å logic:
M
<
1
<
1
2
<
1
2