355
CHAPTER 16 INTERRUPT AND TEST FUNCTIONS
User’s Manual U11302EJ4V0UM
Figure 16-15. Multiple Interrupt Servicing Example (2/2)
Example 3. Multiple interrupt servicing is not generated because interrupts are not enabled
Because interrupts are not enabled in interrupt INTxx servicing (an EI instruction is not issued),
interrupt request INTyy is not acknowledged, and multiple interrupt servicing is not generated. The
INTyy request is held pending and acknowledged after execution of 1 instruction of the main
processing.
PR = 0: Higher priority level
IE = 0:
Interrupt request acknowledgment disabled
Main processing
INTxx
servicing
INTyy
servicing
INTxx
(PR = 0)
1 instruction
execution
IE = 0
INTyy
(PR = 0)
IE = 0
RETI
RETI
EI