Rev. 1.0, 02/00, page 106 of 1141
6.3
Interrupt Sources
Interrupt sources com prise external interrupts (IRQ 5 to IRQ 0) and internal interrupts.
6.3.1
External Interrupts
There are six external interrupt sources; IRQ 5 to IRQ 0. O f these, IRQ 1 to IRQ 0 can be used to
restore this chip from standby m ode.
•
IRQ5 to IRQ0 Interrupts:
Interrupts IRQ 5 to IRQ 0 are
requested by an input signal at pins
,54
8
to
,54
3
. Interrupts IRQ5 to IRQ0 have the following features:
(a) Using IEGR, it is possible to select whether an interrupt is requested by a falling edge,
rising edge, or both edges, at pin
,54
3
.
(b)
Using IEGR, it is possible to select whether an interrupt is requested by a falling edge or
rising edge at pins
,54
8
to
,54
4
.
(c)Enabling or disabling of interrupt requests IRQ 5 to IRQ 0 can be selected w ith IEN R.
(d)The interrupt control level can be set w ith ICR.
(e)The status of interrupt requests IRQ 5 to IRQ 0 is indicated
in IRQR. IRQR flags can be
cleared to 0 by software.
Figure 6.2 shows a block diagram of interrupts IRQ5 to IRQ0.
Clear signal
R
S
Q
Edge detection
circuit
IRQnEG
IRQnF
IRQnE
Note: n = 5 to 0
IRQn interrupt
request
input
Figure 6.2 Block Diagram of Interrupts IRQ5 to IRQ0