206
Table 8.1
Port Functions (cont)
Port
Description
Pins
Mode
1
*
1
Mode
2
*
1,
*
2
Mode
3
*
1,
*
2
Mode
4
Mode
5
Mode
6
*
2
Mode
7
*
2
Port E
8-bit I/O
port
Built-in
MOS input
pull-up
PE
7
/D
7
to
PE
0
/D
0
In 8-bit bus mode:
I/O port
In 16-bit bus mode:
data bus input/output
I/O port
In 8-bit bus mode: I/O port
In 16-bit bus mode: data bus
input/output
I/O port
Port F
8-bit I/O
port
Schmitt-
triggered
input (
IRQ3
to
IRQ0
)
PF
7
/
When DDR = 0:
input port
When DDR = 1 (after
reset): output
When
DDR = 0
(after
reset):
input port
When
DDR = 1:
output
When DDR = 0: input port
When DDR = 1 (after reset):
output
When
DDR = 0
(after
reset):
input port
When
DDR = 1:
output
PF
6
/
AS
PF
5
/
RD
PF
4
/
HWR
PF
/
LWR
/
IRQ3
AS
,
RD
,
HWR
,
LWR
output
I/O port
AS
,
RD
,
HWR
,
LWR
output
I/O port
I/O port
also func-
tioning as
interrupt
input pins
(
IRQ3
to
IRQ0
)
I/O port
also func-
tioning as
interrupt
input pins
(
IRQ3
to
IRQ0
)
PF
/
WAIT
/
IRQ2
When WAITE = 0
(after reset): I/O port
also functioning as
interrupt input pin
(
IRQ2
)
When WAITE = 0 (after reset):
I/O port also functioning as
interrupt input pin (
IRQ2
)
When WAITE = 1:
WAIT
input also
functioning as
interrupt input pin
(
IRQ2
)
When WAITE = 1:
WAIT
input
also functioning as interrupt
input pin (
IRQ2
)
PF
/
BACK
/
IRQ1
PF
/
BREQ
/
IRQ0
When BRLE = 0
(after reset): I/O port
also functioning as
interrupt input pins
(
IRQ1
,
IRQ0
)
When BRLE = 0 (after reset):
I/O port also functioning as
interrupt input pins (
IRQ1
,
IRQ0
)
When BRLE = 1:
BREQ
input,
BACK
output also
functioning as
interrupt input pins
(
IRQ1
,
IRQ0
)
When BRLE = 1:
BREQ
input,
BACK
output also functioning
as interrupt input pins (
IRQ1
,
IRQ0
)