Datasheet

V850ES/JG3 CHAPTER 24 LOW-VOLTAGE DETECTOR (LVI)
R01UH0015EJ0300 Rev.3.00 Page 710 of 870
Sep 30, 2010
24.4 Operation
Depending on the setting of the LVIM.VIMD bit, an interrupt signal (INTLVI) or an internal reset signal is generated.
How to specify each operation is described below, together with timing charts.
24.4.1 To use for internal reset signal
<To start operation>
<1> Mask the interrupt of LVI.
<2> Select the voltage to be detected by using the LVIS.LVIS0 bit.
<3> Set the LVIM.LVION bit to 1 (to enable operation).
<4> Insert a wait cycle of 0.2 ms (max.) or more by software.
<5> By using the LVIM.LVIF bit, check if the supply voltage > detected voltage.
<6> Set the LVIMD bit to 1 (to generate an internal reset signal).
Caution If the LVIMD bit is set to 1, the contents of the LVIM and LVIS registers cannot be changed until a
reset request other than LVI is generated.
Figure 24-2. Operation Timing of Low-Voltage Detector (LVIMD Bit = 1)
Supply voltage (VDD)
LVI detected voltage
(2.95 V (TYP.))
LVION bit
LVI detected signal
Internal reset signal
(active low)
LVI reset request signal
Delay
Clear
Delay
Time