CHAPTER 22 LOW-VOLTAGE DETECTOR
Preliminary User’s Manual U16315EJ1V0UD
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(2) When used as interrupt
•
When starting operation
<1>
Mask the LVI interrupt (LVIMK = 1).
<2>
Set the detection voltage using bits 2 to 0 (LVIS2 to LVIS0) of the low-voltage detection level selection
register (LVIS).
<3>
Set bit 4 (LVIE) of the low-voltage detection register (LVIM) to 1 (enables reference voltage generator
operation).
<4>
Use software to instigate a wait of at least 2 ms.
<5>
Set bit 7 (LVION) of LVIM to 1 (enables LVI operation).
<6>
Use software to instigate a wait of at least 0.2 ms.
<7>
Confirm that “supply voltage (V
DD
) > detection voltage (V
LVI
)” at bit 0 (LVIF) of LVIM.
<8>
Clear the interrupt request flag of LVI (LVIIF) to 0.
<9>
Release the interrupt mask flag of LVI (LVIMK).
<10> Execute the EI instruction (when vector interrupts are used).
Caution
If “use POC” is selected by a mask option, procedures <3> and <4> are not required.
•
When stopping operation
Either of the following procedures must be executed.
•
When using 8-bit memory manipulation instruction:
Write 00H to LVIM.
•
When using 1-bit memory manipulation instruction:
Clear LVION to 0 first, and then clear LVIE to 0.