Datasheet

Rev.6.00 Oct.28.2004 page 293 of 1016
REJ09B0138-0600H
9.5 Port 4
9.5.1 Overview
Port 4 is an 8-bit input-only port. Port 4 pins also function as A/D converter analog input pins (AN0 to AN7) and D/A
converter analog output pins (DA0 and DA1). Port 4 pin functions are the same in all operating modes. Figure 9-4 shows
the port 4 pin configuration.
P4
7
P4
6
P4
5
P4
4
P4
3
P4
2
P4
1
P4
0
(input)/
(input)/
(input)/
(input)/
(input)/
(input)/
(input)/
(input)/
AN7 (input)/DA1 (output)
AN6 (input)/DA0 (output)
AN5 (input)
AN4 (input)
AN3 (input)
AN2 (input)
AN1 (input)
AN0 (input)
Port 4 pins
Port 4
Figure 9-4 Port 4 Pin Functions
9.5.2 Register Configuration
Table 9-8 shows the port 4 register configuration. Port 4 is an input-only port, and does not have a data direction register
or data register.
Table 9-8 Port 4 Registers
Name Abbreviation R/W Initial Value Address*
Port 4 register PORT4 R Undefined H'FF53
Note: * Lower 16 bits of the address.
Port 4 Register (PORT4): The pin states are always read when a port 4 read is performed.
Bit:76543210
P47 P46 P45 P44 P43 P42 P41 P40
Initial value : —* —* —* —* —* —* —* —*
R/W:RRRRRRRR
Note: * Determined by state of pins P4
7
to P4
0
.
9.5.3 Pin Functions
Port 4 pins also function as A/D converter analog input pins (AN0 to AN7) and D/A converter analog output pins (DA0
and DA1).