Port 4 - Fujitsu MB90895 Series Hardware Manual

CHAPTER 4 I/O PORT
4.6

Port 4

Port 4 is a general-purpose I/O port that also serves as a peripheral resource I/O pin.
Use port 4 by switching between the resource pin and the general-purpose I/O port.
The configuration, pin assignment, block diagram of the pins, and registers for port 4
are shown below.
I Configuration of Port 4
Port 4 consists of the following three elements:
• General-purpose I/O port, resource I/O pin (P40/SIN1 to P44/RX)
• Port 4 data register (PDR4)
• Port 4 direction register (DDR4)
I Pin Assignment of Port 4
• The pin is used either a resource pin or a general-purpose I/O pin
• Since the port serves as a resource pin, it cannot be used as a general-purpose I/O port when used as a
resource.
• When using port 4 as the input pin of the resource, set the pin corresponding to the resource in the
DDR4 as an input port.
• When using the port as the output of the resource, set the output of the corresponding resource to
enabled.Port 4 functions as the output pin of the resource regardless of the settings of the DDR4.
Table 4.6-1 shows pin assignment of port 4.
Table 4.6-1 Pin Assignment of Port 4
Pin
Port Name
Name
P40/
SIN1
P41/
SCK1
Port 4 P42/
SOT1
P43/TX
P44/RX
Reference: For the circuit type, see Section 1.7 I/O Circuit.
178
Port Function
P40 SIN1
P41 SCK1
General
-
P42 purpose SOT1
I/O
P43 TX
P44 RX
Resource
CMOS
UART1 serial data
CMOS (hysteresis)/
input
Automotive/CMOS
UART1 serial clock
I/O
UART1 serial data
CMOS
output
CMOS (hysteresis)/
CAN controller
Automotive
send output
CAN controller
receive input
I/O Type
Circu
Type
Input Output
CMOS
CMOS
it
H
D