CHAPTER 13 INTERRUPT FUNCTIONS
User’s Manual U17446EJ3V1UD
234
Figure 13-10. Example of Multiple Interrupts (2/2)
Example 3. A priority is controlled by the multiple interrupts
The vector interrupt enable state is set for INTP0, INTP1, and INTTMH1.
(Interrupt priority INTP0 > INTP1 > INTTMH1 (refer to
Table13-1
))
INTP0
EI
PMK0 = 1
IE = 0
EI
INTP1
RETI
IE = 0
PMK0 = 0
IE = 0
RETI
RETI
INTTMH1
Main processing
INTTNH1 servicing
INTP1 servicing
INTP0 servicing
In the interrupt INTTMH1 servicing, servicing is performed such that the INTP1 interrupt is given priority, since the
INTP0 interrupt was first masked.
Afterwards, once the interrupt mask for INTP0 is released, INTP0 processing through multiple interrupts is
performed.
IE = 0: Interrupt request acknowledgment disabled
13.4.3 Interrupt request pending
Some instructions may keep pending the acknowledgment of an instruction request until the completion of the
execution of the next instruction even if the interrupt request (maskable interrupt and external interrupt) is generated
during the execution. The following shows such instructions (interrupt request pending instruction).
•
Manipulation instruction for interrupt request flag registers 0, 1 (IF0, IF1)
•
Manipulation instruction for interrupt mask flag registers 0, 1 (MK0, MK1)
Содержание 78K0S/KB1+
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