External Interrupts (Int - Renesas 7700 FAMILY User Manual

INTERRUPTS

4.10 External interrupts (INT

4.10 External interrupts (INT
An external interrupt request occurs by input signals to the INT
interrupt request can be selected by the level sense/edge sense select bit and the polarity select bit (bits
5 and 4 at addresses 7D
interrupt request.
___
When using P6 /INT
2 0
address 10 (port P6 direction register) to "0." (Refer to Figure 4.10.2.)
16
The signals input to the INT
Additionally, even when using the pins P6
can obtain the pin's state by reading bits 2 to 4 at address E
Note: When selecting an input signal's falling or "L" level as the occurrence factor of an interrupt request,
make sure that the input signal is held "L" for 250 ns or more. When selecting an input signal's rising
or "H" level as that, make sure that the input signal is held "H" for 250 ns or more.
Table 4.10.1 Occurrence factor of INT
b5
b4
0
0
Interrupt request occurs at falling of the signal input to the INT
0 1
Interrupt request occurs at rising of the signal input to the INT
1
0
Interrupt request occurs while the INT
1
1
Interrupt request occurs while the INT
___
The INT interrupt request occurs by always detecting the INT
i
___
not use the INT interrupt, set the INT
i
4–20
___
interrupt)
i
___
i
to 7F ) shown in Figure 4.10.1. Table 4.10.1 lists the occurrence factor of INT
16 16
___
to P6 /INT pins as input pins of external interrupts, set the corresponding bits at
4 2
___
pin require "H" or "L" level width of 250 ns or more independent of the f(X
i
___
/INT
2
___
interrupt request
i
___
INT
___
interrupt's priority level to level 0.
i
7751 Group User's Manual
interrupt)
___
(i = 0 to 2) pin. The occurrence factor of
i
___
to P6 /INT as the input pins of external interrupt, the user
0 4 2
(port P6 register).
16
interrupt request occurrence factor
i
___
pin level is "H" (level sense).
i
___
pin level is "L" (level sense).
i
___
pin's state. Accordingly, when the user does
i
___
pin (edge sense).
i
___
pin (edge sense).
i
___
i
).
IN