bµi 6
Vµo ra vµ chip
®iÒu khiÓn vµo ra 8255
!"
# $% &' ! "
"
()(
)*+,-.!/%01
234,5&6 !/
7+,89"/
,:!;
,<=
>?
1. Giíi thiÖu
@AB
7C;7+,89$D
7!/
%
@E5 F
@
7189GH
IHD1
3/
æ J
@
%!
+&6
K6 L9IA/
MNL9M>O
&6 + P
1L/ QMNR
&6 STM!
P,
U,V!P+
+&6
@V!P+MQ
,
•KW,!P ,U,
B5&',M!2#XB2 !!P
Y(
@N
>Z
+,
Y2
2#XB2
7C#1[ \HA1==7RYX\
K
K(
]
,P
K2
K(
@N&6
7+,
^YX_
K2
GH`
H
$%&';
1C M/ a b, !P . C
#
1C M/ ML [ P #
c 1
d1
#
Le, a, . !/ %
(
f;
] !!P+;
gH+h
g&W,%P+
GH` L9 f Y*K S
M ,f !i > Z P %
%P+
ML[ HA1==7RYX ;“ ”
1P1
R>Z==7L9LMN
>ZY(dY2j,TYK(dYK2%
YXk
1P1
R,h%GH`
&,,YXL9,5 QMN&6
YK(dYK2
1
f,?,S
%/L9eO
#1,f,?,1
#
R&,
"YX^l_L9+.2#XB2
GH`/mh Q
Y(
@N
>Z
+,
Y2
2#XB##
7C#3P[ \G*YXR
=l7\
n(
]K(d
K2MN&6
+,
n2
K(
1 MN, ừ à
K2
GHD
H H
oKW,M!&6 2#XB## !!P
7C#3P[ \G*YXR
l7\
Y(
@N
>Z
+,
Y2
2#XB##
K(]
K#MN&6
K2+,
K(
1m,PK#
K2
GHD
1V!<;
K6 IA/U,
VQMN,?,,<
^(d((N_RQSL9+ P
L/N,&6
],b,mpRM>
SL9 /MNT
M!P,
34M>^MR,P_+
MN&6 +,SV
!P+qM!P,
U,
@
U,
Y
U,
X
U,
A
@!&6
]
]4
]V!
Y
]V!
@
I@(dI@2I(dII#dI2
IY(dIY2
Be:+
2. Chip ®iÒu khiÓn vµo ra
8255
IY
IY
IY
IY(
*K
Y
Y(
I2
I)
I
I#
I(
I
I
I
I@(
I@
I@
IY#
IY
IY)
IY2
K(
K
K
K
K#
K
K)
K2
$
I@2
I@)
I@
I@#
I@
#(
=
#
2
)
)
2
#
=
(
(
=
#
2
)
)
2
#
=
(
Y
7C
DK
B
`D
DkBk1
! "
( ^ e
,f_
U, IYRI@RXAL9 O
C U, q U,
r V h f M
q q j,
Q,m,M
U, IY I@ ! U,
q f b, M< /
TM"U,I
f b, M<
/"
3 , 6, ! !P h
" f b, Tf F
%M</
@< / T C U
j, T P ,6 M>
j,!
3 % &' M> N5 &', %
M</ !/
@/s&6 L9/MN
&6 "!/
3/ L9 j, M V M/s
&6 S j, T %
P % B1DH@k " !/
r !/ O &6 R !/
j,M,:,5Mt,
% P % Yr
^Yu s&,s_
# 1% Yr . P T C
,hM/s&6 s
!/
U, IY ! U,
f b, M< / ?
%TU,IU,@
V.(q
@BD^ OEM_
U, I L9 O C
m,M
7C1m^GH_
K2K)KK#KK
KK(
*V!@
IX
vG
(vH
I@
vG
(vH
4
(v(
v
*V!Y
vGH
(v@BD
4
((v(
(v
0v
IY
vG
(vH
IA
vG
(vH
1,m
]>ZU,
B Y Y( 4
( ( ( U,Y
( ( U,@
( ( U,
( 1 ,
E E rj,4
#$%&' !
o$%&';e,f
IXRIAW,
Y
Y2
7C#)hC%&'
K(
K2
Y(
Y
Y
@
X
A
K(
K2
Y(
Y
GHD
GH`
DK
`D
B
8255
$%&';
L,.C#)
L9>hCLN;U,Y
U,RU,@ U,h
fM"U,
_1C!>ZU,,YR@R
,
M_7i/C!mhC
Q
_7i/ OCU,&6
U,YL9,5U,@
7C1m^GH_
K2K)KK#KK
KK(
*V!@
IX
vG
(vH
I@
vG
(vH
4
(v(
v
*V!Y
vGH
(v@BD
4
((v(
(v
0v
IY
vG
(vH
IA
vG
(vH
1,m
f;
_>ZU,LLN;
B YY( ]>ZU,
(((( (( 7 U,Y
(((( ( =7 U,@
(((( ( Y7 U,
(((( @7 1,
M_1m =(7q((((((@
_Le,C[VLN;
3H$YXR=(7 wIYvRI@vRIv
HA1@7RYX w,5,
G*YXR7 w h/&6 mIY
HA1=7RYX w,5&6 U,I@
HA1Y7RYX wU,I
A2
A7
7C#2hC%&'
D0
D7
A0
A1
A
B
CL
CU
D0
D7
A0
A1
IOR
IOW
RD
CS
WR
o$%&';$e,f
U,IXIA
$%&';
^C#2_L9>h
C;IYRIAdU,RI@RIX
U,
_1C!>ZU,IYRI@RI
1]r^,_
M_1C!mhC
Q
_XOCO&6 OIY
,5I@ROIX,5IA