Holtek HT45F23A Manual page 56

Low Voltage Reset – LVR
The microcontroller contains a low voltage reset circuit in order to monitor the supply voltage of the
devices, which is selected via a configuration option. If the supply voltage of the devices drop to within a
range of 0.9V~V
LVR
devices internally. The LVR includes the following specifications: For a valid LVR signal, a low voltage,
i.e., a voltage in the range between 0.9V~V
characteristics. If the low voltage state does not exceed t
reset function. One of a range of specified voltage values for V
options.
Watchdog Time-out Reset during Normal Operation
The Watchdog time-out Reset during normal operation is the same as a hardware RES pin reset
except that the Watchdog time-out flag TO will be set to "1".
Watchdog Time-out Reset during SLEEP or IDLE Mode
The Watchdog time-out Reset during SLEEP or IDLE Mode is a little different from other kinds
of reset. Most of the conditions remain unchanged except that the Program Counter and the Stack
Pointer will be cleared to "0" and the TO flag will be set to "1". Refer to the A.C. Characteristics for
t details.
SST
Note: The t
SST
The t
SST
Rev. 1.40
TinyPower Flash MCU with OPA & Comparators
TM
such as might occur when changing the battery, the LVR will automatically reset the
must exist for greater than the value t
LVR
L V R
I n t e r n a l R e s e t
Note: t is power-on delay, typical time=100ms
RSTD
Low Voltage Reset Timing Chart
WDT Time-out
Internal Reset
Note: t is power-on delay, typical time=100ms
RSTD
WDT Time-out Reset during Normal Operation Timing Chart
WDT Time-out
Internal Reset
is 15~16 clock cycles if the system clock source is provided by ERC or HIRC.
is 1024 clock for HXT or LXT. The t
WDT Time-out Reset during Idle/Sleep Timing Chart
56
HT45F23A/HT45F24A
specified in the A.C.
LVR
, the LVR will ignore it and will not perform a
LVR
can be selected using configuration
LVR
t t
R S T D + S S T
t
RSTD
t
SST
is 1~2 clock for LIRC.
SST
March 29, 2019