UPD78F0890GK(A)-GAJ-AX NEC, UPD78F0890GK(A)-GAJ-AX Datasheet - Page 110

• Manufacturer Part Number: UPD78F0890GK(A)-GAJ-AX
• Description: 8BIT MCU, 128K FLASH, 7K RAM, LQFP
• Manufacturer: NEC

Specifications of UPD78F0890GK(A)-GAJ-AX

• Controller Family/series: UPD78F
• No. Of I/o's: 55
• Ram Memory Size: 7KB
• Cpu Speed: 20MHz
• No. Of Timers: 10
• No. Of Pwm: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 128KB
• Oscillator Type: External, Internal

5.2.10 Port 12
using port mode register 12 (PM12). When used as an input port only for P120, use of an on-chip pull-up resistor can
be specified by pull-up resistor option register 12 (PU12).
resonator for main system clock, connecting resonator for subsystem clock, external clock input for main system clock,
external clock input for subsystem clock.
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This port can also be used for external interrupt input, potential input for external low-voltage detector, connecting
Reset signal generation sets port 12 to input mode.
Figures 5-19 and 5-20 show block diagrams of port 12.
Port 12 is a 5-bit I/O port with an output latch. Port 12 can be set to the input mode or output mode in 1-bit units
Cautions 1. When using the P121 to P124 pins to connect a resonator for the main system clock (X1, X2)
2. Connect P121/X1 as follows when writing the flash memory with a flash programmer.
or subsystem clock (XT1, XT2), or to input an external clock for the main system clock
(EXCLK) or subsystem clock (EXCLKS), the X1 oscillation mode, XT1 oscillation mode, or
external clock input mode must be set by using the clock operation mode select register
(OSCCTL) (for detail, see 6.3 (5) Clock operation mode select register (OSCCTL)). The reset
value of OSCCTL is 00H (all of the P121 to P124 pins are I/O port pins). At this time, setting
of the PM121 to PM124 and P121 to P124 pins is not necessary.
- P121/X1: When using this pin as a port, connect it to V
recommended) (in the input mode) or leave it open (in the output mode).
The above connection is not necessary when writing the flash memory by means of self
programming.
CHAPTER 5 PORT FUNCTIONS
User’s Manual U17554EJ4V0UD
SS
via a resistor (10 kΩ: