HD6433044 Hitachi Semiconductor, HD6433044 Datasheet - Page 263

• Manufacturer Part Number: HD6433044
• Description: (HD64 Series) Hitachi Single-Chip Microcomputer
• Manufacturer: Hitachi Semiconductor

9.3.2 Register Descriptions
Table 9-3 summarizes the registers of port 2.
Table 9-3 Port 2 Registers
Address*
H'FFC1
H'FFC3
H'FFD8
Note: * Lower 16 bits of the address.
Port 2 Data Direction Register (P2DDR): P2DDR is an 8-bit write-only register that can select
input or output for each pin in port 2.
Modes 1 to 4 (Expanded Modes with On-Chip ROM Disabled): P2DDR values are fixed at 1
and cannot be modified. Port 2 functions as an address bus.
Modes 5 and 6 (Expanded Modes with On-Chip ROM Enabled): Following a reset, port 2 is
an input port. A pin in port 2 becomes an address output pin if the corresponding P2DDR bit is set
to 1, and a generic input port if this bit is cleared to 0.
Mode 7 (Single-Chip Mode): Port 2 functions as an input/output port. A pin in port 2 becomes an
output port if the corresponding P2DDR bit is set to 1, and an input port if this bit is cleared to 0.
Bit
Modes
1 to 4
Modes
5 to 7
Initial value
Read/Write
Initial value
Read/Write
Name
Port 2 data direction register
Port 2 data register
Port 2 input pull-up MOS
control register
P2 DDR
7
—
W
7
1
0
P2 DDR
6
—
W
6
1
0
P2 DDR
5
—
W
5
1
0
Port 2 data direction 7 to 0
These bits select input or
output for port 2 pins
250
Abbreviation
P2DDR
P2DR
P2PCR
P2 DDR
4
—
W
4
1
0
P2 DDR
3
—
W
3
1
0
R/W
W
R/W
R/W
P2 DDR
2
—
Modes 1 to 4
H'FF
H'00
H'00
W
2
1
0
P2 DDR
Initial Value
1
—
W
1
1
0
Modes 5 to 7
H'00
H'00
H'00
P2 DDR
0
—
W
0
1
0