Register Descriptions; Table 7.13 Port 8 Registers - Hitachi H8/3062 Hardware Manual

7.9.2

Register Descriptions

Table 7.13 summarizes the registers of port 8.

Table 7.13 Port 8 Registers

Address *
Name
H'EE007 Port 8 data direction
register
H'FFFD7 Port 8 data register
Note: * Lower 20 bits of the address in advanced mode
Port 8 Data Direction Register (P8DDR): P8DDR is an 8-bit write-only register that can select
input or output for each pin in port 8.
Bits 7 to 5 are reserved. They are fixed at 1, and cannot be modified.
Bit
Initial value
Modes
1 to 4
Read/Write
Initial value
Modes
5 to 7
Read/Write
• Modes 1 to 5 (Expanded Modes)
When bits in P8DDR bit are set to 1, P8
P8DDR are cleared to 0, the corresponding pins become input ports.
In modes 1 to 4 (expanded modes with on-chip ROM disabled), following a reset P8
as the CS output, while CS
0
ROM enabled), following a reset CS
• Modes 6 and 7 (Single-Chip Mode)
Port 8 is a generic input/output port. A pin in port 8 becomes an output port if the
corresponding P8DDR bit is set to 1, and an input port if this bit is cleared to 0.
P8DDR is a write-only register. Its value cannot be read. All bits return 1 when read.
Abbreviation
P8DDR
P8DR
7 6 5
— — —
1 1 1
— — —
1 1 1
— — —
Reserved bits
4
to CS
are input ports. In mode 5 (expanded mode with on-chip
1 3
to CS
0
R/W Mode 1 to 4
W H'F0
R/W H'E0
4 3
P8 DDR P8 DDR
4 3
1 0
W W
0 0
W W
Port 8 data direction 4 to 0
These bits select input or
output for port 8 pins
become CS to CS
to P8
1 0
are all input ports.
3
Initial Value
Mode 5 to 7
H'E0
H'E0
2 1
P8 DDR P8 DDR P8 DDR
2 1
0 0
W W
0 0
W W
output pins. When bits in
3
functions
4
0
0
0
W
0
W
191