Table of Contents
Advertisement
Section 8 I/O Ports
8.5
Port 4
8.5.1
Overview
Port 4 is a 3-bit I/O port and 1-bit input port, configured as shown in figure 8.4.
8.5.2
Register Configuration and Description
Table 8.11 shows the port 4 register configuration.
Table 8.11 Port 4 Registers
Name
Port data register 4
Port control register 4
1. Port Data Register 4 (PDR4)
Bit
7
—
Initial value
1
Read/Write
—
PDR4 is an 8-bit register that stores data for port 4 pins P4
bits are set to 1, the values stored in PDR4 are read, regardless of the actual pin states. If port 4 is
read while PCR4 bits are cleared to 0, the pin states are read.
Upon reset, PDR4 is initialized to H'F8.
Rev. 6.00 Aug 04, 2006 page 226 of 680
REJ09B0145-0600
Port 4
Figure 8.4 Port 4 Pin Configuration
Abbr.
PDR4
PCR4
6
5
4
—
—
—
1
1
1
—
—
—
P4
/IRQ
3
0
P4
/TXD
2
32
P4
/RXD
1
32
P4
/SCK
0
32
R/W
Initial Value
R/W
H'F8
W
H'F8
3
2
P4
P4
3
2
1
0
R
R/W
to P4
. If port 4 is read while PCR4
2
0
Address
H'FFD7
H'FFE7
1
0
P4
P4
1
0
0
0
R/W
R/W
Advertisement
Table of Contents
