INTERRUPTS
6.10 External interrupts
6.10 External interrupts
The external interrupts consist of INTi interrupts.
6.10.1 INT
An INT (i = 0 to 7) interrupt request occurs by an input signal to pin INT
factor of the INT interrupt request.
When using any of pins P5 /INT , P5
external interrupt, be sure to clear the port P5 direction register’s bit. (See Figure 6.10.2.)
i
interrupt
i
i
. Table 6.10.1 lists the occurrence
i
1
1
2
/INT
2
, P5
3
/INT
3
, P5
5
/INT
5
, P5
6
/INT
6
, P5
7
/INT as an input pin of the
7
When using pin P4OUTCUT/INT
P4 to P4 in the input mode. (Refer to section “5.2.3 Pin P4OUTCUT/INT
When using pin P6OUTCUT/INT
P6 to P6 in the input mode. (Refer to section “5.2.4 Pin P6OUTCUT/INT
The signal input to pin INT
By reading out the INT read bit (See Figure 6.10.1.), the state of pin INT
0
as an input pin of an external interrupt (pin INT
0
), be sure to use port pins
0
7
0
.”)
4
as an input pin of an external interrupt (pin INT
4
), be sure to use port pins
0
7
4
.”)
i
requires “H” or “L” level width of 250 ns or more, independent of f(XIN).
can be read out.
i
i
Note: Selection of the interrupt occurrence factor requires the following conditions:
• when an input signal’s falling edge or “L” level is selected, be sure that “L” level width ≥ 250 ns.
• when an input signal’s rising edge or “H” level is selected, be sure that “H” level width ≥ 250 ns.
Table 6.10.1 Occurrence factor of INT
i
interrupt request
Occurrence factor of interrupt request
(An interrupt request occurs when the
Polarity select bit
Level sense/Edge sense select bit
(bit 4 at addresses 7D16 to
,
(bit 5 at addresses 7D16 to 7F16
input signal of pin INT is as follows.)
i
7F16, 6E16, 6F16, FD16 to FF16
)
6E16, 6F16, FD16 to FF16
)
Falling edge (Edge sense)
Rising edge (Edge sense)
“H” level (Level sense)
“L” level (Level sense)
0
1
0
1
INT
0
to INT
7
0
0
1
1
The INT
i
interrupt request occurs by detecting the state of pin INT
i
all the time. Therefore, when the user
does not use an INT
i
interrupt, be sure to set the INT interrupt’s priority level to 0.
i
7905 Group User’s Manual Rev.1.0
6-18
RENESAS [ RENESAS TECHNOLOGY CORP ]
