R-22JT
22
Pin No.
Signal
I/O
Description
21
P45
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.
22-24
P44-P42
OUT
Digit selection signal.
Signal similar to P45.
25
INT1
IN
Signal synchronized with commercial power source frequency.
This is basic timing for all time processing of LSI.
26
INT0
IN
Connected to GND through resistor.
27
RESET
IN
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.
28
P71
OUT
Memory (EEPROM) clock output.
29
P70
IN/OUT
Memory (EEPROM) data input/output.
30
XIN
IN
Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with respect to
XOUT terminal.
31
XOUT
OUT
Internal clock oscillation frequency control output.
Output to control oscillation input of XIN.
32
VSS
IN
Connected to GND.
33
P27
IN
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.
34
P26
IN
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.
35
P25
IN
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.
36
P24
IN
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.
37-38
P23-P22
OUT
Terminal not used.
39-40
P21-P20
OUT
Segment data signals.
The relation between signals and indicators are as follows:
Signal
Segment
Signal
Segment
P21,P20 .......... 1
P07,P06 ............. 6
P17.P16 .......... 2
P05,P04 ............. 7
P15,P14 .......... 3
P03,P02 ............. 8
P13,P12 .......... 4
P01,P00 ............. 9
P11,P10 .......... 5
41-48
P17-P10
OUT
Segment data signal.
Signal similar to P21.
49-56
P07-P00
OUT
Segment data signal.
Signal similar to P21.
H
L
+5V
ß(60Hz)
P42
P43
P44
P45
GND
H : +5V
L : GND
16.7 msec
+5V
GND
ß(60Hz)
