Register Descriptions; Table 7.3 Port 2 Registers - Hitachi H8/3062 Hardware Manual

7.3.2

Register Descriptions

Table 7.3 summarizes the registers of port 2.
Table 7.3 Port 2 Registers
Address *
Name
H'EE001 Port 2 data direction register
H'FFFD1 Port 2 data register
H'EE03C Port 2 input pull-up MOS control
register
Note: * Lower 20 bits of the address in advanced mode
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.
Bit
P2 DDR
Initial value
Modes
1 to 4
Read/Write
Initial value
Modes
5 to 7
Read/Write
• Modes 1 to 4 (Expanded Modes with On-Chip ROM Disabled)
P2DDR values are fixed at 1. Port 2 functions as an address bus.
• Mode 5 (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.
• Modes 6 and 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.
In modes 1 to 4, P2DDR bits are always read as 1, and cannot be modified.
7 6 5
P2 DDR P2 DDR
7 6 5
1 1 1
— — —
0 0 0
W W W
Abbreviation R/W Modes 1 to 4 Modes 5 to 7
P2DDR W
P2DR R/W H'00
P2PCR R/W H'00
4 3
P2 DDR P2 DDR
4 3
1 1
— —
0 0
W W
Port 2 data direction 7 to 0
These bits select input or
output for port 2 pins
Initial Value
H'FF H'00
H'00
H'00
2 1
P2 DDR P2 DDR P2 DDR
2 1
1 1
— —
0 0
W W
0
0
1
—
0
W
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