ST72324xx-Auto
Supply, reset and clock management
The interrupt on the rising edge is used to inform the application that the VDD warning state
is over.
If the voltage rise time trv is less than 256 or 4096 CPU cycles (depending on the reset delay
selected by option byte), no AVD interrupt will be generated when VIT+(AVD) is reached.
If trv is greater than 256 or 4096 cycles then:
● If the AVD interrupt is enabled before the VIT+(AVD) threshold is reached, then two AVD
interrupts will be received: the first when the AVDIE bit is set, and the second when the
threshold is reached.
● If the AVD interrupt is enabled after the VIT+(AVD) threshold is reached, then only one
AVD interrupt will occur.
Figure 15. Using the AVD to monitor VDD
t(s) VDD
duc VIT+(AVD)
ro VIT-(AVD)
P VIT+(LVD)
te VIT-(LVD)
Early warning interrupt
(power has dropped, MCU not
not yet in reset)
Vhyst
trv Voltage rise time
bsole AVDF bit
0
- O AVD Interrupt
Request
) if AVDIE bit = 1
ct(s LVD RESET
1
Reset value
Interrupt process
1
0
Interrupt process
Obsolete Produ 6.5.3
Low power modes
Table 10.
Mode
Wait
Effect of low power modes on SI
Description
No effect on SI. AVD interrupt causes the device to exit from Wait mode.
Halt The CRSR register is frozen.
6.5.4
Interrupts
The AVD interrupt event generates an interrupt if the AVDIE bit is set and the interrupt mask
in the CC register is reset (RIM instruction).
M
Table 11. AVD interrupt control/wake-up capability
Interrupt event
Event flag Enable Control bit Exit from WAIT Exit from HALT
AVD event
AVDF
AVDIE
Yes
No
Doc ID 13841 Rev 1
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