upd78f0730 Renesas Electronics Corporation., upd78f0730 Datasheet - Page 440

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

17.4.1 When used as reset
(1) When detecting level of supply voltage (V
440
• 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> Wait until it is checked that (supply voltage (V
<6> Set bit 1 (LVIMD) of LVIM to 1 (generates internal reset signal when supply voltage (V
Figure 17-5 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
When using 8-bit memory manipulation instruction:
Write 00H to LVIM.
When using 1-bit memory manipulation instruction:
Clear LVIMD to 0 and then LVION to 0.
voltage (V
2. If supply voltage (V
after the processing in <3>.
signal is not generated.
LVI
)).
CHAPTER 17 LOW-VOLTAGE DETECTOR
Preliminary User’s Manual U19014EJ1V0UD
DD
) ≥ detection voltage (V
DD
)
DD
) ≥ detection voltage (V
LVI
µ
) when LVIMD is set to 1, an internal reset
s (MAX.)).
LVI
)) by bit 0 (LVIF) of LVIM.
DD
) < detection