Port 1; Overview; Port 1 Registers; Pin Functions - Hitachi H8/500 Series Hardware Manual

9.2 Port 1

9.2.1 Overview

Port 1 is an 8-bit input/output port with the pin configuration shown in figure 9-1. All pins have
dual functions, except that in the single-chip mode pins 4, 3, and 2 do not have the WAIT, BREQ,
and BACK functions. (because the CPU does not access an external bus.)
Outputs from port 1 can drive one TTL load and a 90pF capacitive load. They can also drive a
Darlington transistor pair.
Pin
P1
7
P1
6
P1
5
Port P1
4
1 P1
3
P1
2
P1
1
P1
0

9.2.2 Port 1 Registers

Register Configuration: Table 9-2 lists the registers of port 1.
Table 9-2 Port 1 Registers
Name
Port 1 data direction register
Port 1 data register
Port 1 control register
*1 Bits 1 and 0 are read-only.
*2 Bits 1 and 0 are undetermined. Other bits are initialized to "0."
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Expanded Modes
/ TMO P1 (input/output) / TMO (output)
7
/ IRQ P1 (input/output) / IRQ
1 6
/ IRQ P1 (input/output) / IRQ
0 5
/ WAIT P1 (input/output) / WAIT (input)
4
/ BREQ P1 (input/output) / BREQ (input)
3
/ BACK P1 (input/output) / BACK (output) P1
2
/ E P1 (input) / E (output)
1
/ ø P1 (input) / ø (output)
0
Figure 9-1 Pin Functions of Port 1
Abbreviation
P1DDR
P1DR
P1CR
Single-Chip Mode
P1 (input/output) / TMO (output)
7
(input) P1 (input/output) / IRQ
1 6
(input) P1 (input/output) / IRQ
0 5
P1 (input/output)
4
P1 (input/output)
3
(input/output)
2
P1 (input) / E (output)
1
P1 (input) / ø (output)
0
Read/Write Initial Value
W H'03
R/W *1 Undetermined
R/W H'87
142
(input)
1
(input)
0
Address
H'FF80
*2 H'FF82
H'FFFC