Datasheet

Section 9 I/O Ports
Rev.6.00 Sep. 27, 2007 Page 394 of 1268
REJ09B0220-0600
9.8 Port A
9.8.1 Overview
Port A is an 8-bit I/O port. Port A pins also function as address bus outputs and interrupt input
pins (IRQ
4
to IRQ
7
). The pin functions change according to the operating mode. IRQ
4
to IRQ
7
input can be switched to P5
0
to P5
3
by setting the IRQPAS bit in SYSCR to 1. The address output
or port output function can be selected by means of bits A23E to A20E in PFCR1.
Port A has a built-in MOS input pull-up function that can be controlled by software. Pins PA
7
to
PA
4
are Schmitt-triggered inputs.
Figure 9.7 shows the port A pin configuration.
PA
7
/ A
23
/ IRQ
7
PA
6
/ A
22
/ IRQ
6
PA
5
/ A
21
/ IRQ
5
PA
4
/ A
20
/ IRQ
4
PA
3
/ A
19
PA
2
/ A
18
PA
1
/ A
17
PA
0
/ A
16
PA
7
(I/O) / A
23
(output) / IRQ
7
(input)
PA
6
(I/O) / A
22
(output) / IRQ
6
(input)
PA
5
(I/O) / A
21
(output) / IRQ
5
(input)
PA
4
(output) / A
20
(output)
A
19
(output)
A
18
(output)
A
17
(output)
A
16
(output)
Port A pins Pin functions in modes 4 and 5
Pin functions in mode 6
PA
7
(I/O) / IRQ
7
(input)
PA
6
(I/O) / IRQ
6
(input)
PA
5
(I/O) / IRQ
5
(input)
PA
4
(I/O) / IRQ
4
(input)
PA
3
(I/O)
PA
2
(I/O)
PA
1
(I/O)
PA
0
(I/O)
Pin functions in mode 7
PA
7
(I/O) / A
23
(output) / IRQ
7
(input)
PA
6
(I/O) / A
22
(output) / IRQ
6
(input)
PA
5
(I/O) / A
21
(output) / IRQ
5
(input)
PA
4
(I/O) / A
20
(output) / IRQ
4
(input)
PA
3 (input) / A
19
(output)
PA
2
(input) / A
18
(output)
PA
1 (input) / A
17
(output)
PA
0
(input) / A
16
(output)
Port A
Figure 9.7 Port A Pin Functions