UPD78F0988AGC-8BS Renesas Electronics America, UPD78F0988AGC-8BS Datasheet - Page 279

• Manufacturer Part Number: UPD78F0988AGC-8BS
• Manufacturer: Renesas Electronics America

Specifications of UPD78F0988AGC-8BS

• Lead Free Status / Rohs Status: Supplier Unconfirmed

INTxx is being serviced. Before each interrupt request is acknowledged, the EI instruction is always issued and
interrupt requests are enabled.
not performed because the priority of INTyy is lower than that of INTxx. INTyy is held pending and is acknowledged
after one instruction of the main servicing has been executed.
This multiple interrupt example shows two interrupt requests, INTyy and INTzz, being acknowledged while interrupt
INTyy, which is generated while INTxx is being serviced, is not acknowledged and multiple interrupt servicing is
PR = 0:
PR = 1:
IE = 0:
INTxx
(PR = 1)
Example 2. Multiple interrupt is not generated because of its priority
Main servicing
Higher priority level
Lower priority level
Acknowledging interrupt request is disabled
EI
INTxx
(PR = 0)
Example 1. Multiple interrupt is generated twice
Main servicing
Figure 14-14. Multiple Interrupt Example (1/2)
1 instruction
execution
IE = 0
EI
CHAPTER 14 INTERRUPT FUNCTIONS
INTyy
(PR = 0)
User’s Manual U13029EJ7V1UD
INTxx
servicing
RETI
EI
IE = 0
INTyy
(PR = 1)
IE = 0
INTxx
servicing
IE = 0
INTzz
(PR = 0)
RETI
EI
INTyy
servicing
RETI
EI
INTyy
servicing
RETI
IE = 0
INTzz
servicing
RETI
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