UPD78F0138 NEC, UPD78F0138 Datasheet - Page 422

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

• Checking reset cause
(2) When used as interrupt
422
Check that “supply voltage (V
0 (LVIF) of the low-voltage detection register (LVIM). Clear bit 0 (LVIIF) of interrupt request flag register 0L (IF0L)
to 0 and enable interrupts (EI).
In a system where the supply voltage fluctuation period is long in the vicinity of the LVI detection voltage, wait for
the supply voltage fluctuation period, check that “supply voltage (V
flag, and then enable interrupts (EI).
Figure 23-6. Example of Software Processing After Release of Reset (2/2)
DD
Reset processing by
low-voltage detector
Check reset cause
WDTRF of RESF
CLMRF of RESF
) > detection voltage (V
LVIRF of RESF
register = 1?
register = 1?
register = 1?
CHAPTER 23 LOW-VOLTAGE DETECTOR
No
No
Yes
User’s Manual U16228EJ2V0UD
Yes
Yes
No
LVI
)” in the servicing routine of the LVI interrupt by using bit
Power-on-clear/external
Reset processing by
Reset processing by
reset generated
watchdog timer
clock monitor
DD
) > detection voltage (V
LVI
)” using the LVIF