R-25JT-F
24
Pin No. Signal I/O Description
H
L
+5V
ß(60Hz)
P42
P43
P44
P45
GND
H : +5V
L : GN
16.7 msec
+5V
GND
ß(60Hz)
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 P05,P04 ............. 7
P17.P16 .......... 2 P03,P02 ............. 8
P15,P14 .......... 3 P01,P00 ............. 9
P13,P12 .......... 4
P11,P10 .......... 5
P07,P06 .......... 6