UPD784938 Datasheet, PDF (178/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 6 PORT FUNCTIONS
6.8.4 On-chip pull-up resistors
P60 to P67 incorporate pull-up resistors. Use of these internal resistors when pull-up is necessary enables the number of
parts and the mounting area to be reduced.
Whether or not an on-chip pull-up resistor is to be used can be specified for each pin by setting the PUOL6 bit of the pull-
up resistor option register L (PUOL) and the port 6 mode register (PM6).
When PUOL6 is 1, the on-chip pull-up resistors of the pins for which input is specified by the PM6 (PM6n = 1, n = 0 to 7) are
enabled .
PUOL
Figure 6-58. Pull-Up Resistor Option Register L (PUOL) Format
7
6
5
4
3
2
1
0 Address After reset R/W
0 PUOL6 PUOL5 PUOL4 PUOL3 PUOL2 PUOL1 PUOL0 0FF4EH
00H
R/W
PUOL6 Port 6 Pull-Up Resistor Specification
0 Not used in port 6
1 Used in port 6
Remark When STOP mode is entered, setting PUOL to 00H is effective for reducing the current consumption.
Figure 6-59. Pull-Up Specification (Port 6)
VDD
P67
P66
P65
Input
buffer
Internal
bus
P61
P60
(PUOL)
PUOL6
Port 6 mode register
(PM6)
178
Preliminary User’s Manual U13987EJ1V0UM00