Port 4; Overview; Register Configuration And Description - Hitachi H8/3937 Series Hardware Manual

8.5

Port 4*

Note: * P4 /IRQ , only, is a chip internal input port.
3 0
8.5.1

Overview

Port 4 is a 3-bit I/O port and 1-bit input internal port, configured as shown in figure 8-4. P4
is an internal function that performs interfacing to the FLEX™ decoder incorporated in the chip.
It cannot be connected to an IC outside the chip.
Port 4
Note: : Connected inside the chip (P4
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
154
P4 /IRQ
3 0
P4 /TXD
2 32
P4 /RXD
1
32
P4 /SCK
0
32
Figure 8-4 Port 4 Pin Configuration
Abbrev.
PDR4
PCR4
READY
only).
3
R/W Initial Value
R/W H'F8
W H'F8
/IRQ
3 0
FLEX™
decoder
Address
H'FFD7
H'FFE7