sh66k31c SinoWealth Micro-Electronics Corp. Ltd, sh66k31c Datasheet - Page 22

• Manufacturer Part Number: sh66k31c
• Description: Mask 4-bit Micro-controller
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

Application Circuits (For Reference Only)
AP1: Remote Control (48 Keys)
(1) Operating Voltage: V
(2) Oscillator: Ceramic 400kHz - 4MHz
(3) PORTA, D: I/O Buffers
(4) PORTB and C: Input Buffers
(5) Option RESET pin with pull-high; and C1 can be removed. For high reliability, C1 is better to be added.
(6) R1 = 0 is possible, but the REM specification is revised to reduce power consumption
(7) I
AP2: Remote Control (40 Keys)
Operating Voltage: V
The simplified code option would not sink any power consumption since PORTD.1 short with other I/O ports. Because
PORTD.1 can be programmed as input only with pull-high, so that PORTB or PORTC can be scanned out to detect PORTD.1
option. After detection, PORTD.1 pull-high resistor can be turned off by software, if there is an option selected. If there is no
option selected, then the pull-high resistor cannot be turned off, so that PORTD.1 would not be floating.
Application Note:
The RESET pin must be connected to V
REM
= -5mA (V
REM
DD
= 1V).
= 3.0V.
DD
= 3.0V
47µF
47µF
10kΩ
10kΩ
V
V
DD
DD
DD
C1
C1
20p
20p
4MHz
, when the user verifies the function of the remote control with SH66P31B OTP type IC.
20p
20p
0.1µF
R1
0.1µF
R1
V
GND
REM
OSCO
OSCI
RESET
DD
GND
REM
OSCO
OSCI
RESET
V
DD
22
PORTD.1
PORTD.0
PORTC.3
PORTC.2
PORTC.1
PORTC.0
PORTB.3
PORTB.2
PORTB.1
PORTB.0
PORTA.3
PORTA.2
PORTA.1
PORTA.0
PORTD.1
PORTD.0
PORTC.3
PORTC.2
PORTC.1
PORTC.0
PORTB.3
PORTB.2
PORTB.1
PORTB.0
PORTA.3
PORTA.2
PORTA.1
PORTA.0
Simplified Custom Code
switch can be closed
Selection only one
SH66K31C