SEM ICON D UCTOR
µ,PD825 1
AC (Control u n it I C 54)
Doto bus
µ PD7800
µ,PD825 5AC-5 (Control u n it I C 2 , 5 3 )
.JJPD780 0
0
R
16
t+5VI
G N O
Doto bus
)
r "'
R e a d i n p u t
R O
W r i t e i n p u t
W R
Port address
i np u t
A l
Port address
i n p u t
AO
Reset
RESET
Chip select
CS
74LS l38
11
A t I C 2 : Y 3
@
I i i
At I C 53 : Y 2
@
8
D a t a
bus
buffer
R / W
con t rol
D o t o
bus
buffer
R / R
control
l og i c
MODEM
contro l
Tran s
m i t
buffer
I P - S l
T X D
TX
Not use
N o t use
SN 7404
58
T X D
R X D
05 (4040>
@
p i n
C
Bo ro te :
48001
Group A
control
Group B
control
I n ner
doto bus
8
8
8 b i t
I nner
doto bus
Basic function
A ,
A o
0
0
0
0
1
0
1
0
0
0
0
0
0
1
0
1
0
0
1
1
0
x
x
1
1
1
0
8
8
R D
0
0
0
1
1
1
1
x
0
R X O
RX
µ P07800 I N T I
@
p i n
R X C
SYNOE T/BO
N ot use
8
4
4
Group A
Port A
( 8
b i t )
G rou p A
Por t
C
(Upper4 bit)
G rou p B
Port
C
(Lower 4 bit)
G roup B
Por t B
(8
b i t )
PA7
l
1
•ro -"
� 1
110
Port
c
PCO
18
-�l-"
PBO
WR
F u nction
1
D ata bus
+-
Port A
1
D ata b u s
+-
Port
B
1
D ata b u s
+-
Port C
0
Port A
+-
D ata b u s
0
Port
B
+-
D ata bu·s
0
P o rt C
+-
D ata bus
0
C o n t r o l register
+-
D ata b u s
x
D ata bus is i n h i g h i m p e d a n c e
statu s
1
C o m b i n ation is i n h i bited
"O" shows low level
(L)
" 1 "
shows high level ( H )
TS-440S
33
