ST7FLITE29 STMICROELECTRONICS [STMicroelectronics], ST7FLITE29 Datasheet - Page 31

• Manufacturer Part Number: ST7FLITE29
• Description: 8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, DATA EEPROM, ADC, TIMERS, SPI
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

SYSTEM INTEGRITY MANAGEMENT (Cont’d)
7.6.2 Auxiliary Voltage Detector (AVD)
The Voltage Detector function (AVD) is based on
an analog comparison between a V
V
ply voltage (V
for falling voltage is lower than the V
ence value for rising voltage in order to avoid par-
asitic detection (hysteresis).
The output of the AVD comparator is directly read-
able by the application software through a real
time status bit (AVDF) in the SICSR register. This
bit is read only.
Caution: The AVD functions only if the LVD is en-
Figure 19. Using the AVD to Monitor V
IT+(AVD)
AVDF bit
AVD INTERRUPT
REQUEST
IF AVDIE bit = 1
LVD RESET
V
V
V
V
IT+(AVD)
IT+(LVD)
IT-(LVD)
IT-(AVD)
reference value and the V
V
AVD
DD
). The V
0
IT-(AVD)
1
reference value
IT+(AVD)
DD
INTERRUPT Cleared by
IT-(AVD)
main sup-
V
Early Warning Interrupt
(Power has dropped, MCU not
not yet in reset)
DD
hyst
refer-
reset
and
RESET
abled through the option byte.
7.6.2.1 Monitoring the V
The AVD voltage threshold value is relative to the
selected LVD threshold configured by option byte
(see
If the AVD interrupt is enabled, an interrupt is gen-
erated when the voltage crosses the V
V
In the case of a drop in voltage, the AVD interrupt
acts as an early warning, allowing software to shut
down safely before the LVD resets the microcon-
troller. See
IT-(AVD)
section 15.1 on page
threshold (AVDF bit is set).
Figure
19.
1
INTERRUPT Cleared by
DD
123).
Main Supply
hardware
0
ST7LITE2
IT+(LVD)
31/131
or
1