Operation Of Key-Input Interrupt - Renesas M16C Series User Manual

M30245 Group

2.14.2 Operation of Key-Input Interrupt

The following is an operation of key-input interrupt. Figure 2.14.4 shows an example of a circuit that uses
the key-input interrupt, Figure 2.14.5 shows an example of operation of key-input interrupt, and Figure
2.14.6 shows the setting procedure of key-input interrupt.
Operation
www.DataSheet4U.com
Figure 2.14.4. Example of circuit using the key-input interrupt
P10
P10
P10
P10
P10
input
Key input
Key input
interrupt processing
Figure 2.14.5. Example of operation of key-input interrupt
Rev.2.00 Oct 16, 2006
REJ09B0340-0200
(1) Set the direction register of the ports to be changed to key-input interrupt pins to input, and set
the pull-up function.
(2) Setting the key-input interrupt control register and setting the interrupt enable flag makes the
interrupt-enabled state ready.
(3) If a falling edge is input to either KI
(1) Enter to stop mode
output
4
output
5
output
6
output
7
to P10
0 3
Key OFF
page 265 of 354
_____
through KI , the key-input interrupt request bit goes to "1".
0 7
V
P10 REF
4
P10
5
P10
6
P10
7
P10 / KI
0 0
P10 / KI
1 1
P10 / KI
2 2
P10 / KI
3 3
(2) Cancel stop mode
(3) Key scan
(4) Enter to stop mode
Key ON Key OFF
2. Key-Input Interrupt
I/O port
Key matrix scan
Key ON