Rev. 1.00
48
August 29, 2018
Rev. 1.00
49
August 29, 2018
HT45F6530
AC Voltage Regulator Flash MCU
HT45F6530
AC Voltage Regulator Flash MCU
Low Voltage Reset – LVR
The microcontroller contains a low voltage reset circuit in order to monitor the supply voltage of the
device. The LVR function is always enabled during normal operation with a specific LVR voltage
V
LVR
. The actual V
LVR
value is fixed at 2.1V. If the supply voltage of the device drops to within a
range of 0.9V~V
LVR
such as might occur when changing the battery in battery powered applications,
the LVR will automatically reset the device internally and the LVRF bit in the RSTFC register will
also be set to 1. For a valid LVR signal, a low supply voltage, i.e., a voltage in the range between
0.9V~V
LVR
must exist for a time greater than that specified by t
LVR
in the LVR/LVD Electrical
Characteristics. If the low supply voltage state does not exceed this value, the LVR will ignore
the low supply voltage and will not perform a reset function. Note that the LVR function will be
automatically disabled when the device enters the SLEEP or IDLE mode.
LVR
Internal Reset
t
RSTD
+ t
SST
Note: t
RSTD
is power-on delay, typical time=50ms.
Low Voltage Reset Timing Chart
• RSTFC Register
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
LVRF
—
WRF
R/W
—
—
—
—
—
R/W
—
R/W
POR
—
—
—
—
—
x
—
0
“x”: unknown
Bit 7~3
Unimplemented, read as “0”
Bit 2
LVRF
: LVR function reset flag
0: Not occur
1: Occurred
This bit is set to 1 when a specific Low Voltage Reset situation condition occurs. This
bit can only be cleared to 0 by the application program.
Bit 1
Unimplemented, read as “0”
Bit 0
WRF
: WDTC register software reset flag
Described elsewhere
Watchdog Time-out Reset during Normal Operation
The Watchdog time-out Reset during normal operations in the FAST or SLOW mode is the same as
the hardware low voltage reset except that the Watchdog time-out flag TO will be set to “1”.
WDT Time-out
Internal Reset
t
RSTD
+ t
SST
Note: t
RSTD
is power-on delay, typical time=16.7ms.
WDT Time-out Reset during Normal Operation Timing Chart