BAT32G1x9 user manual | Chapter 31 Voltage detection circuit
1092 / 1149
Rev.1.02
Chapter 31 Voltage detection circuit
31.1 The function of the voltage detection circuit
The voltage detection circuit sets the operating mode and detection voltage (V
LVDH
, V
LVDL
, V
LVD
) by
option byte (000C1H). The Voltage Sense (LVD) circuit has the following functions.
• Compare supply voltage (VDD) with sense voltage (VLVDH, VLVDL, VLVD). , which generates an internal
reset or internal interrupt signal.
• The sense voltage of the supply voltage (VLVDH, VLVDL) can select 12 detection levels by the option
byte (see "Section 34." Chapter Option Bytes").
• Can also be operated in deep sleep mode.
• When the supply voltage rises, the reset state must be maintained by voltage detection circuits or external
resets before the supply voltage reaches the operating voltage range shown in the AC characteristics of
the data sheet; When the supply voltage drops, it must be reset by transferring in deep sleep mode,
voltage detection circuitry, or external reset before the supply voltage falls below the operating voltage
range. The operating voltage range depends on the setting of the user option byte (000C2H/010C2H).
(a) Interrupt & Reset mode (LVIMDS1, LVIMDS0=1, 0).
Select 2 sense voltages (V
LVDH
, V
LVDL
) and high voltage sense level (V LVDH) via option byte 000C1H) is
used to de-reset or generate an interrupt, and a low voltage sense level (V
LVDL
) is used to generate a reset.
(b) Reset mode (LVIMDS1, LVIMDS0=1, 1) of the option bytes
Use the 1 sense voltage (V
LVD
) selected by option byte 000C1H to generate or de-reset.
(c) Interrupt mode (LVIMDS1, LVIMDS0=0, 1) of the options
Use the 1 sense voltage (V
LVD
) selected by option byte 000C1H to generate an interrupt or de-reset. In
each mode, the following interrupt signals and internal reset signals are generated.
Interrupt &
Reset mode
(LVIMDS1, LVIMDS0=1, 0)
Reset mode
(LVIMDS1, LVIMDS0=1, 1)
Break mode
(LVIMDS1, LVIMDS0=0, 1)
When the operating voltage drops, it is detected
VDD
＜
When V
DD
≥V
LVD
is detected, the internal reset
is released;
After a reset occurs, the
LVD's internal
reset state follows
VLVDH, generates an interrupt request signal;
When detected
When detectedV
DD
＜
V
LVD
, an internal reset
is generated.
Continue until V
DD
≥
V
LVD
. When detected
VDD
＜
VLVDLwhen an internal reset is
generated;
When V
DD
≥
V
LVD
, the internal reset of
LVD
is released.
When VDD≥VLVDH is detected, the internal
reset is released.
If detected after removing the internal reset
of lvd
V
DD
＜
V
LVD
orV
DD
≥V
LVD
When, yes
Generates an Interrupt Request Signal
(INTLVI).
When running a voltage detection circuit, it is possible to confirm whether the supply voltage is greater
than or equal to the sense voltage or less than the sense voltage by reading the voltage detection flag (LVIF:
bit0 of the voltage detection register (LVIM)).
If a reset occurs, set bit0 (LVIRF) of the reset control flag register (RESF) to "1". For details on RESF
registers, refer to Chapter 29 Reset Functions.
