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R01UH0336EJ0102 Rev.1.02
Page 39 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 2 Port Functions
2.2 Overview
The microcontroller has various pins for input/output functions, known as ports.
The ports are organized in port groups.
The microcontroller also has several control registers to allocate non-general
purpose input/output functions to the pins.
For a description of the terms pin, port, and port group, see Section 2.2.1,
Terms.
Features summary
• I/O ports
• Multiplexed with input/output pin functions for other peripheral modules
• Able to specify input/output in bit units
• Edge detection
• Software pull-up
• Noise cancellation
2.2.1
Terms
In this section, the following terms are used.
• Pin
Denotes the physical pin. Every pin is denoted by a unique pin number.
A pin can be switched to several modes for use.
The pin function allocated to a pin depends on the selected mode.
• Port group
Denotes a group of pins. The pins of a port group have a common set of port
mode control registers.
• Port mode/Port
A pin in port mode works as a general purpose input/output pin. It is then
called “port”.
The corresponding name is Pn_m. For example, P0_1 denotes port 1 of port
group 0. It is referenced as “port P0_1”.
• Alternative mode
In alternative mode, a pin can be used for in various non-general purpose
input/output functions, for example as the input/output pin of on-chip
peripherals.
The corresponding pin name depends on the selected function.
For example, pin INTP0 denotes the pin for one of the external interrupt
inputs.
Note that two different names can refer to the same physical pin, for
example P0_0 and INTP0. The different names indicate the function in
which the pin is being operated.
• Port type
“Port type” is set by setting a configuration register for the given port.