Register Descriptions - Hitachi H8/3062 Hardware Manual

Single-chip microcomputer

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Register Descriptions

Table 7.8 summarizes the registers of port 5.

Port 5 Registers

Address* Name

H'EE004 Port 5 data direction register

H'FFFD4 Port 5 data register

H'EE03F Port 5 input pull-up MOS control

Note: * Lower 20 bits of the address in advanced mode.

Port 5 Data Direction Register (P5DDR): P5DDR is an 8-bit write-only register that can select

input or output for each pin in port 5.

Bits 7 to 4 are reserved. They are fixed at 1, and cannot be modified.

Initial value

Initial value

• Modes 1 to 4 (Expanded Modes with On-Chip ROM Disabled)

P5DDR values are fixed at 1. Port 5 functions as an address bus output.

• Mode 5 (Expanded Modes with On-Chip ROM Enabled)

Following a reset, port 5 is an input port. A pin in port 5 becomes an address output pin if the

corresponding P5DDR bit is set to 1, and an input port if this bit is cleared to 0.

• Modes 6 and 7 (Single-Chip Mode)

Port 5 functions as an input/output port. A pin in port 5 becomes an output port if the

corresponding P5DDR bit is set to 1, and an input port if this bit is cleared to 0.

In modes 1 to 4, P5DDR bits are always read as 1, and cannot be modified.

Reserved bits

Abbreviation R/W

Initial Value

Modes 1 to 4 Modes 5 to 7

Port 5 data direction 3 to 0

These bits select input or

output for port 5 pins