UPD17717 Datasheet, PDF (21/408 Pages) NEC – 4-BIT SINGLE-CHIP MICROCONTROLLERS WITH DEDICATED HARDWARE FOR DIGITAL TUNING SYSTEM

µPD17717, 17718, 17719
1.3 Connections of Unused Pins
It is recommended to connect unused pins as follows:
Table 1-1. Connections of Unused Pins (1/2)
Port pin
Pin Name
I/O Mode
P0D3/AD3-P0D0/AD0 Input
P1C3/AD5
P1C2/AD4
P1C1/AMIFC^{Note 2}
P1C0/FMIFC^{Note 2}
P1A3/INT4
P1A2/INT3
P1A1
P1A0/TM0G
P1B3
N-ch open-drain
P1B2/PWM2-P1B0/PWM0 output
P0A3/SDA
I/O^{Note 3}
P0A2/SCL
P0A1/SCK2
P0A0/SO2
P0B3/SI2
P0B2/SCK3
P0B1/SO3/TxD
P0B0/SI3/RxD
P0C3-P0C0
P1D3
P1D2
P1D1/BEEP1
P1D0/BEEP0
P2A2
P2A1/FCG1
P2A0/FCG0
P2B3-P2B0
P2C3-P2C0
P2D2/SCK
P2D1/SB1
P2D0/SB0
Recommended Connections of Unused Pins
Individually connect to GND via resistor^{Note 1}.
Set in port mode and individually connect to VDD or GND
via resistor^{Note 1}.
Individually connect to GND via resistor^{Note 1}.
Set to low-level output by software and then open.
Set in general-purpose input port mode by software and
individually connect to VDD or GND via resistor^{Note 1}.
Notes 1. If a pin is externally pulled up (connected to VDD via resistor) or pulled down (connected to GND
via resistor) with a high resistance, the pin almost enters a high-impedance state, increasing the
current (through-current) consumption of the port. Generally, the resistance of a pull-up or pull-
down resistor is several 10 kΩ, though it depends on the application circuit.
2. Do not set these pins as AMIFC and FMIFC pins; otherwise, the current consumption will increase.
3. The I/O ports are set in the general-purpose I/O port mode at power-ON reset, when reset by the
RESET pin, or when reset due to overflow or underflow of the watchdog timer or the stack.
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