HD6435348R Hitachi Semiconductor, HD6435348R Datasheet - Page 168

• Manufacturer Part Number: HD6435348R
• Description: Single-Chip Microcomputer
• Manufacturer: Hitachi Semiconductor

9.3.2 Port 2 Registers
Register Configuration: Table 9-5 lists the registers of port 2.
Table 9-5 Port 2 Registers
Name
Port 2 data direction register
Port 2 data register
1. Port 2 Data Direction Register (P2DDR)—H'FE81
Bit
Initial value
Read/Write
P2DDR is an 8-bit register that selects the direction of each pin in port 2.
Single-Chip Mode: A pin functions as an output pin if the corresponding bit in P2DDR is set to
1, and as an input pin if the bit is cleared to 0.
Bits 4 to 0 can be written but not read. An attempt to read this register does not cause an error, but
all bits are read as 1, regardless of their true values.
Bits 7 to 5 are reserved. They cannot be modified and are always read as 1.
At a reset and in the hardware standby mode, P2DDR is initialized to H'E0, making all five pins
input pins. P2DDR is not initialized in the software standby mode, so if a P2DDR bit is set to 1
when the chip enters the software standby mode, the corresponding pin continues to output the
value in the port 2 data register.
Expanded Modes: All bits of P2DDR are fixed at 1 and cannot be modified.
—
—
7
1
—
—
6
1
Abbreviation
P2DDR
P2DR
—
—
5
1
P2
151
4
W
4
DDR P2
0
Read/Write
W
R/W
3
W
3
0
DDR P2
Initial Value
H'E0
H'E0
2
W
2
DDR P2
0
1
W
1
0
DDR P2
Address
H'FE81
H'FE83
0
W
0
DDR
0