Sharp ER-A750 Service Manual page 39

2-3. OPC1 (F256004PJ)
1) General description
The OPC1 is a gate array of integrated peripheral circuits of RS-
232/Simple IRC interface.
One chip of the OPC1 is equipped with four communication circuits.
(Three of them are for RS-232 only: UNIT 0 ~ 2, one is for selection
of simple IRC/RS-232: UNIT 3)
The ER-A750 uses UNIT0 (RS-232 interface) and UNIT7 (RS-232 inter-
face).
UNIT NO.
UNIT0 RS-232
UNIT1 RS-232
UNIT2 RS-232
UNIT3 RS-232/IRC
Each UNIT of the OPC1 has the following functions:
1 Timer function
Used for the timer between characters in data reception.
2 Address decode
USART chip select output and own select.
3 Interruption control
RSRQ, TRRQ output using outputs from USART (TRNRDY,
TRNEMP, RCVRDY, BRK) and RS-232 control signals (CI, CTS,
CD) as interruption factors.
(For the simple IRC, TRNEMP is excluded.)
* RSRQ: For RS-232
TRRQ: For IRC
4 Simple IRC send/receive control (UNIT3 only) : Not used
2) Pin configuration
CS3
CS2
TRNEMP3
BRK3
TRANDY3
RCVRDY3
RXDATA0
TRCK
RES
OPTCS
GND
RSRQ
Purpose ER-A750
Used.
Used.
Not used.
Not used.
1
2
3
4
5
6
7
8
9
10
D0 11
D1 12
D2 13
D3 14
15
16
D4
D5 17
D6 18
D7 19
20
A0 21
A1 22
A2 23
A3 24
A4 25
OPC1
F256004PJ
7 – 9
75 SL12
74 RCVRDY2
73 RCVDT1
72 RCVRDY1
71 TRNRDY1
70 BRK1
69 DB7
68 DB6
67 DB5
66 DB4
65 GND
64 DB3
63 DB2
62 DB1
61 DB0
60 TRNEMP1
59 TRNRDY0
58 RCVDT0
57 RCVRDY0
56 TRNEMP0
55 BRK0
54 SL30
53 XOUT
52 SL22
51 RES