Sharp ER-A450T Service Manual page 22

2) Block diagram
DATA BUS
OPC1~USART
Common input
3) Pin description
Pin
Name ER-A770
NO.
1 SL00 VCC
2 SL01 GND
3 SL02 GND
4 SL10 GND
5 SL11 GND
6 SL12 GND
7 SL20 GND
8 SL21 GND
9 SL22 GND
10 SL30 GND
11 SL31 GND
12 SL32 GND
13 /CD0 /DCD1
14 BRK0 BRK1
15 TRNEMP0 TRENMP1
16 RCVRDY0 RCVRDY1
17 TRNRDY0 TRNRDY1
18 /CTS0 /CTS1
19 RCVDT0 RCVDT1
20 VCC VCC
21 GND GND
22 /CI0 /CI1
23 /RTS0 /RTS1
24 /CS0 /CS1
25 /CD1 /DCD2
BAUD RATE GENERATOR
USART
A
USART
I/O Description
ISU RS-232/UNIT0
channel select
ISU
ISU
ISU RS-232/UNIT1
channel select
ISU
ISU
ISU RS-232/UNIT2
channel select
ISU
ISU
ISU RS-232/UNIT3
channel select
ISU
ISU
RS-232 control
IS
signal /CD input
IS RS-232 break signal
RS-232 transmission
IS
buffer empty signal
RS-232 data reception
IS
enable signal
RS-232 transmission
IS
enable signal
RS-232 clear to
IS
send signal
RS-232 reception
IS
data signal
+5V
GND
RS-232 control
IS
signal /CI input
RS-232 request to
O
send signal
RS-232 chip select
O
signal
RS-232 control
IS
signal /CD input
OPC2
OPC1
BAUD RATE GENERATOR
USART USART
B
C
Pin
Name
NO.
26 BRK1
27 TRNEMP1
28 RCVRDY1
29 TRNRDY1
30 /CTS1
31 RCVDT1
32 /CI1
33 /RTS1
34 /CS1
35 /CD2
36 TRNEMP2
37 RCVRDY2
38 TRNRDY2
39 CTS2Z
40 RCVDT2
41 /CI2
42 /CS2
43 /CD3
44 BRK3
45 TRNEMP3
46 RCVRDY3
47 TRNRDY3
48 /CTS3
49 RCVDT3
50 /CI3
51 /CS3
52 D0
53 D1
4 – 14
USART
D
ER-A770 I/O Description
BRK2 IS GND
TRENMP2 IS GND
RCVRDY2 IS GND
TRNRDY2 IS GND
/CTS2 IS +5V
RS-232 reception
RCVDT2 IS
data signal
RS-232 control
/CI2 IS
signal /CI input
RS-232 request to
/RTS2 O
send signal
RS-232 chip select
/CS2 O
signal
VCC IS +5V
TRENMP3 IS GND
RCVRDY3 IS GND
TRNRDY3 IS GND
/CTS3 IS +5V
RCVDT3 IS GND
VCC IS +5V
/CS3 O NU
RS-232: /CD,
/SINT IS
IN-LINE : /P1
GND IS GND
GND IS GND
GND IS GND
GND IS GND
GND IS GND
GND IS GND
GND IS GND
RS-232/INLINE chip
/SRCS O
select signal
D0 IO Data bus (CPU)
D1 IO Data bus (CPU)