NEC 78K0 Series User Manual page 544

(2) When detecting level of input voltage from external input pin (EXLVI)
• When starting operation
<1> Mask the LVI interrupt (LVIMK = 1).
<2> Set bit 2 (LVISEL) of the low-voltage detection register (LVIM) to 1 (detects level of input voltage from
external input pin (EXLVI)).
<3> Set bit 7 (LVION) of LVIM to 1 (enables LVI operation).
<4> Use software to wait for an operation stabilization time (10
<5> Wait until it is checked that (input voltage from external input pin (EXLVI) ≥ detection voltage (V
1.21 V (TYP.))) by bit 0 (LVIF) of LVIM.
<6> Set bit 1 (LVIMD) of LVIM to 1 (generates internal reset signal when input voltage from external input pin
(EXLVI) < detection voltage (V
Figure 24-6 shows the timing of the internal reset signal generated by the low-voltage detector. The numbers
in this timing chart correspond to <1> to <6> above.
Cautions 1. <1> must always be executed. When LVIMK = 0, an interrupt may occur immediately
after the processing in <3>.
544
CHAPTER 24 LOW-VOLTAGE DETECTOR
= 1.21 V (TYP.))).
EXLVI
Preliminary User's Manual U17260EJ3V1UD
µ
Note
s (MAX.) ).
=
EXLVI