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MC80F0104/0204
Preliminary
82
Mar. 2005 Ver 0.2
Figure 18-3 Interrupt Request Flag Register
18.1 Interrupt Sequence
An interrupt request is held until the interrupt is accepted
or the interrupt latch is cleared to “0” by a reset or an in-
struction. Interrupt acceptance sequence requires 8 cycles
of f
XIN
(2
µ
s at f
XIN
=4MHz) after the completion of the
current instruction execution. The interrupt service task is
terminated upon execution of an interrupt return instruc-
tion [RETI].
18.1.1 Interrupt acceptance
1. The interrupt master enable flag (I-flag) is cleared to
“0” to temporarily disable the acceptance of any follow-
ing maskable interrupts. When a non-maskable inter-
rupt is accepted, the acceptance of any following
interrupts is temporarily disabled.
2. Interrupt request flag for the interrupt source accepted is
cleared to “0”.
3. The contents of the program counter (return address)
and the program status word are saved (pushed) onto the
stack area. The stack pointer decreases 3 times.
4. The entry address of the interrupt service program is
read from the vector table address and the entry address
is loaded to the program counter.
5. The instruction stored at the entry address of the inter-
rupt service program is executed.
INT3IF
R/W
INT0IF
Timer/Counter 0 interrupt request flag
INITIAL VALUE: 0000 0000
B
ADDRESS: 0EC
H
IRQH
INT1IF
MSB
LSB
SIOIF
T0IF
UARTRIF UARTTIF
INT2IF
R/W
R/W
Serial Communication interrupt request flag
UART Txx interrupt request flag
External interrupt 3 request flag
UART Rx interrupt request flag
R/W R/W
R/W R/W
R/W
External interrupt 2 request flag
External interrupt 1 request flag
External interrupt 0 request flag
R/W
T1IF
INITIAL VALUE: 000- 00-0
B
ADDRESS: 0ED
H
IRQL
T2IF
MSB
-
Timer/Counter 3 interrupt request flag
R/W R/W
Timer/Counter 2 interrupt request flag
Timer/Counter 1 interrupt request flag
LSB
-
ADCIF WDTIF
R/W
R/W R/W
T3IF
-
-
BITIF
Basic Interval Timer interrupt request flag
Watchdog timer interrupt request flag
A/D Converter interrupt request flag
Содержание MC80F0104
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