240
5.9
Port 8
5.9.1
Overview
Port 8 is a 6-bit I/O port. Port 8 pins also function as interrupt input pins (
IRQ0
to
IRQ5
) and
EXDMAC input/output pins (
EDREQ2
,
ETEND2
,
EDACK2
,
EDREQ3
,
ETEND3
, and
EDACK3
). The functions of pins P85 to P80 change according to the operating mode.
The interrupt input pins (
IRQ0
to
IRQ5
) can be switched by making a setting in ITSR.
When pins P85 to P80 are used for IRQ input, they are Schmitt-trigger inputs.
Figure 5.8 shows the port 8 pin configuration.
P85 (I/O) /
EDACK3
(output) /
IRQ5
(input)
P84 (I/O) /
EDACK2
(output) /
IRQ4
(input)
P83 (I/O) /
ETEND3
(output) /
IRQ3
(input)
P82 (I/O) /
ETEND2
(output) /
IRQ2
(input)
P81 (I/O) /
EDREQ3
(input) /
IRQ1
(input)
P80 (I/O) /
EDREQ2
(input) /
IRQ0
(input)
Modes 1, 2, 4, 5, 6, 7 (EXPE = 1)
P85 (I/O) /
EDACK3
(output) /
IRQ5
(input)
P84 (I/O) /
EDACK2
(output) /
IRQ4
(input)
P83 (I/O) /
ETEND3
(output) /
IRQ3
(input)
P82 (I/O) /
ETEND2
(output) /
IRQ2
(input)
P81 (I/O) /
EDREQ3
(input) /
IRQ1
(input)
P80 (I/O) /
EDREQ2
(input) /
IRQ0
(input)
Mode 7 (EXPE = 0)
P85 (I/O) /
IRQ5
(input)
P84 (I/O) /
IRQ4
(input)
P83 (I/O) /
IRQ3
(input)
P82 (I/O) /
IRQ2
(input)
P81 (I/O) /
IRQ1
(input)
P80 (I/O) /
IRQ0
(input)
Port 8
Port 8 pins
Figure 5.8 Port 8 Pin Functions
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