Register Descriptions - Hitachi H8/3032 Series Hardware Manual

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7.2.2 Register Descriptions

Table 7-2 summarizes the registers of port 1.
Table 7-2 Port 1 Registers
Address* Name
H'FFC0 Port 1 data direction register
H'FFC2 Port 1 data register
Note: * Lower 16 bits of the address.
Port 1 Data Direction Register (P1DDR): P1DDR is an 8-bit write-only register that can select
input or output for each pin in port 1.
Bit 7
P1 DDR P1 DDR
7
0
Initial value
W
Read/Write
Mode 1: A pin in port 1 becomes an address output pin if the corresponding P1DDR bit is set to 1,
and a generic input pin if this bit is cleared to 0.
Modes 2 and 3 (Single-Chip Modes): Port 1 functions as an input/output port. A pin in port 1
becomes an output pin if the corresponding P1DDR bit is set to 1, and an input pin if this bit is
cleared to 0.
P1DDR is a write-only register. Its value cannot be read. All bits return 1 when read.
P1DDR is initialized to H'00 by a reset and in hardware standby mode. In software standby mode it
retains its previous setting. If a P1DDR bit is set to 1, the corresponding pin maintains its output
state in software standby mode.
Abbreviation
P1DDR
P1DR
6 5 4 3
P1 DDR P1 DDR P1 DDR
6 5 4 3
0 0 0 0
W W W W
Port 1 data direction 7 to 0
These bits select input or
output for port 1 pins
123
R/W Initial Value
W H'00
R/W H'00
2 1 0
P1 DDR P1 DDR P1 DDR
2 1 0
0 0 0
W W W