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CHAPTER 3 CPU
3.4
Interrupts
The MB89980 series has 12 interrupt request input corresponding to peripheral
functions. An interrupt level can be set independently.
If an interrupt request output is enabled in the peripheral function, an interrupt request
from a peripheral function is compared with the interrupt level in the interrupt
controller. The CPU performs interrupt operation according to how the interrupt is
accepted. The CPU wakes up from standby modes, and returns to the interrupt or
normal operation.
s Interrupt Requests from Peripheral Functions
Table 3.4-1 "Interrupt Request and Interrupt Vector" lists the interrupt requests corresponding to
the peripheral functions. On acceptance of an interrupt, execution branches to the interrupt
processing routine. The contents of interrupt the vector table address corresponding to the
interrupt request specifies the branch destination address for the interrupt processing routine.
An interrupt processing level can be for each interrupt request in the interrupt level setting
registers (ILR1, ILR2, ILR3). Three levels are available.
If an interrupt request with the same or lower level occurs during execution of an interrupt
processing routine, the letter interrupt is not normally processed until the current interrupt
processing routine completes. If interrupt request set the same level occur simultaneously, the
highest priority is IRQ0.
Table 3.4-1 Interrupt Request and Interrupt Vector
Interrupt request
Vector table address
Bit names of the
interrupt level
setting register
Simultaneously-
generated same-
level IRQ priority
Upper
Lower
IRQ0 (External interrupt 1-1)
FFFAH
FFFBH
L01, L00
High
IRQ1 (External interrupt 1-2)
FFF8H
FFF9H
L11, L10
IRQ2 (External interrupt 1-3)
FFF6H
FFF7H
L21, L20
IRQ3 (External interrupt 1-4)
FFF4H
FFF5H
L31, L30
IRQ4 (External interrupt 2)
FFF2H
FFF3H
L41, L40
IRQ5 (8/16-bit timer/counter)
FFF0H
FFF1H
L51, L50
IRQ6 (Vacancy)
FFEEH
FFEFH
L61, L60
IRQ7 (Timebase timer)
FFECH
FFEDH
L71, L70
IRQ8 (Watch prescaler)
FFEAH
FFEBH
L81, L80
IRQ9 (PWM timer 1)
FFE8H
FFE9H
L91, L90
IRQA (PWM timer 2)
FFE6H
FFE7H
LA1,LA0
IRQB (A/D converter)
FFE4H
FFE5H
LB1, LB0
Low