stm8af6166t STMicroelectronics, stm8af6166t Datasheet - Page 17

• Manufacturer Part Number: stm8af6166t
• Description: Automotive 8-bit Mcu, With Up To 128 Kbytes Flash, Eeprom, 10-bit Adc, Timers, Lin, Can, Usart, Spi, I2c, 3 V To 5.5 V
• Manufacturer: STMicroelectronics

STM8AF61xx, STM8AF51xx
5.5.5
5.6
5.6.1
5.6.2
Clock security system (CSS)
The clock security system protects against a system stall in case of an external crystal clock
failure.
In case of a clock failure an interrupt is generated and the high speed internal clock (HSI) is
automatically selected with a frequency of 2 MHz (16 MHz/8).
Timers
Watchdog timers
The watchdog system is based on two independent timers providing maximum security to
the applications.
The WDG timer activity is controlled by option bytes. Once activated the watchdog can not
be disabled by the user program without reset.
Window watchdog timer
The window watchdog is used to detect the occurrence of a software fault, usually
generated by external interferences or by unexpected logical conditions, which cause the
application program to abandon its normal sequence.
The window function can be used to trim the watchdog behavior to match the application
perfectly.
The application software must refresh the counter before time-out and during a limited time
window.
A reset is generated in two situations:
1.
2.
Independent watchdog timer
The independent watchdog peripheral can be used to resolve processor malfunctions due to
hardware or software failures.
It is clocked by the 128 kHZ LSI internal RC clock source, and thus stays active even in case
of a CPU clock failure
The IWDG time base spans from 60 µs to 1 s.
Auto wake-up counter
●
●
●
Timeout: At 16 MHz CPU clock the time-out periode can be adjusted between 75 µs up
to 64 ms.
Refresh out of window: The downcounter is refreshed before its value is lower then the
one stored in the window register.
Used for auto wake-up from active halt mode
Clock source: internal 128 kHz internal low frequency RC oscillator or external clock
Programmable interrupt time from 5 ms up to 1 s (TBD)
Product overview
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