NEC 78K0/KD1 Series User Manual page 381

(2) When used as interrupt
Disable interrupts (DI) in the servicing routine of the LVI interrupt, and check to see if "supply voltage (V
detection voltage (V
LVI
(EI).
In a system where the supply voltage fluctuation period is long in the vicinity of the LVI detection voltage, disable
interrupts (DI), wait for the supply voltage fluctuation period, check that "supply voltage (V
(V )" with the LVIF flag, and then enable interrupts (EI).
LVI
Figure 22-7. Example of Software Processing of LVI Interrupt
• If supply voltage fluctuation is 50 ms or less in vicinity of LVI detection voltage
LVI interrupt servicing
No
50 ms has passed?
(TMIFH1 = 1?)
No
LVIF1 of LVIM
CHAPTER 22 LOW-VOLTAGE DETECTOR
)", by using bit 0 (LVIF) of the low-voltage detection register (LVIM). Then enable interrupts
LVI
LVI interrupt
DI
;
Start timer
(set to 50 ms)
;
Yes
;
register = 0?
Yes
EI
;
Preliminary User's Manual U16315EJ1V0UD
Disable interrupts.
TMIFH1 = 1: Interrupt request is generated
Check that supply voltage (V
DD
Enable interrupts.
) > detection voltage
DD
) > detection voltage (V ).
LVI
) >
DD
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