Sharp R-22GV Service Manual page 24

R-22GV
R-22GT
R-23GT
R-24GT
Pin No. Signal I/O
21 P45 OUT
22-24 P44-P42 OUT
25 INT1 IN
26 INT0 IN
27 RESET IN
28 P71 OUT
29 P70 IN/OUT
30 XIN IN
31 XOUT OUT
32 VSS IN
33 P27 IN
34 P26 IN
35 P25 IN
36 P24 IN
37-38 P23-P22 OUT
39-40 P21-P20 OUT
Digit selection signal.
The relation between digit signal and digit are as
follows:
Digit signal Digit
P42 ..................... 1st.
P43 .................... 2nd.
P44 ..................... 3rd.
P45 ..................... 4th.
Normally, one pulse is output in every ß period,
and input to the grid of the light-emitting diode.
Digit selection signal.
Signal similar to P45.
Signal synchronized with commercial power source frequency.
This is basic timing for all time processing of LSI.
Connected to GND through resistor.
Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is supplied. Temporarily set
to "L" level the moment power is supplied, at this time the LSI is reset. Thereafter set at "H"
level.
Memory (EEPROM) clock output.
Memory (EEPROM) data input/output.
Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with
respect to XOUT terminal.
Internal clock oscillation frequency control output.
Output to control oscillation input of XIN.
Connected to GND.
Signal coming from touch key.
When either one of G-12 line keys on key matrix is touched, a corresponding signal out of
P30, P31, P32, P33, P34 will be input into P27. When no key is touched, the signal is held
at "L" level.
Signal similar to P27.
When either one of G-11 line keys on key matrix is touched, a corresponding signal will be
input into P26.
Signal similar to P27.
When either one of G-10 line keys on key matrix is touched, a corresponding signal will be
input into P25.
Signal similar to P27.
When either one of G-9 line keys on key matrix is touched, a corresponding signal will be
input into P24.
Terminal not used.
Segment data signals.
The relation between signals and indicators are as follows:
Signal Segment Signal
P21,P20 .......... 1 P05,P04 ............. 7
P17.P16 .......... 2 P03,P02 ............. 8
P15,P14 .......... 3 P01,P00 ............. 9
P13,P12 .......... 4
P11,P10 .......... 5
P07,P06 .......... 6
22
Description
ß(60Hz)
P42
P43
P44
P45
Segment
ß(60Hz)
H
L
+5V
GND
H : +5V
L : GND
16.7 msec
+5V
GND