UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 169

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

5.6.4 Internal Pull-Up Resistors
and the mounting area to be reduced.
up resistor option register (PUO) and the port 4 mode register (PM4).
n = 0 to 7) are enabled .
Port 4 incorporates pull-up resistors. Use of these internal resistors when pull-up is necessary enables the number of parts
Whether or not an internal pull-up resistor is to be used can be specified for each pin by means of the PUO4 bit of the pull-
When PUO4 is 1, the internal pull-up resistors of the pins for which input is specified by the PM4 for port 4 (PM4n = 1,
Caution In the PD784021, port 4 is used as the address/data bus, and therefore “0” must be assigned to PUO4
Remark When STOP mode is entered, assigning 00H to PUO is effective in reducing the current consumption.
PUO
so that internal pull-up resistor connection is not performed. The same also applies when port 4 is used
as the address/data bus in the PD784026.
7
0
PUO6
6
PUO5
Figure 5-42 Pull-Up Resistor Option Register (PUO) Format
5
PUO4
4
PUO3
CHAPTER 5 PORT FUNCTIONS
3
PUO2
2
PUO1
1
PUO0
0
PUO4
0FF4EH
Address
0
1
Port 4 Pull-Up Resistor Specification
Not used in port 4
Used in port 4
On Reset
00H
R/W
R/W
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