Serial Interface Circuit - Casio UP-360 Service Manual

3-12. SERIAL INTERFACE CIRCUIT

PC I/F (RC232C)
U18 is latch IC. U18 (HIM232CB) is RS232C transceiver.
TXD, RXD, RTS and CTS are UART communication ports.
LTXD
LDTR#
LRXD
LDSR#
+
C59
+
1uF/25V
C66
1uF/25V
U18
11 14
T1IN T1OUT
10 7
T2IN T2OUT
12 13
R1OUT R1IN
9 8
R2OUT R2IN
1 16
C1+ VCC
3 2
C1- V+
4 6 C60
C2+ V-
5 15
C2- GND
C67
HIN232
1uF/25V 1uF/25V
— 25 —
L1 MPZ2012S300A
L2 MPZ2012S300A
L3 MPZ2012S300A
L4 MPZ2012S300A
VCC
C61
C62 C63 C64 C65
0.1uF
1000pF X 4
FB1
MPZ3216S500A
P1
1
14
2
15
3
16
4
17
5
18
6
19
7
20
8
21
9
22
10
23
11
24
12
25
13
CDS3125-0126