upd78f0730 Renesas Electronics Corporation., upd78f0730 Datasheet - Page 442

• Manufacturer Part Number: upd78f0730
• Description: 8-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

17.4.2 When used as interrupt
(1) When detecting level of supply voltage (V
442
• When starting operation
• When stopping operation
Either of the following procedures must be executed.
•
•
<1> Mask the LVI interrupt (LVIMK = 1).
<2> Set the detection voltage using bit 0 (LVIS0) of the low-voltage detection level selection register (LVIS).
<3> Set bit 7 (LVION) of LVIM to 1 (enables LVI operation).
<4> Use software to wait for an operation stabilization time (10
<5> Confirm that “supply voltage (V
<6> Clear the interrupt request flag of LVI (LVIIF) to 0.
<7> Release the interrupt mask flag of LVI (LVIMK).
<8> Clear bit 1 (LVIMD) of LVIM to 0 (generates interrupt signal when supply voltage (V
<9> Execute the EI instruction (when vector interrupts are used).
Figure 17-6 shows the timing of the interrupt signal generated by the low-voltage detector. The numbers in
this timing chart correspond to <1> to <8> above.
When using 8-bit memory manipulation instruction:
Write 00H to LVIM.
When using 1-bit memory manipulation instruction:
Clear LVION to 0.
voltage (V
LVI
)) (default value).
CHAPTER 17 LOW-VOLTAGE DETECTOR
Preliminary User’s Manual U19014EJ1V0UD
DD
) ≥ detection voltage (V
DD
)
LVI
µ
)” at bit 0 (LVIF) of LVIM.
s (MAX.)).
DD
) < detection