STM8S005C6T6 datasheet(14/103 Pages) STMICROELECTRONICS

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Watchdog timers

4.7

The watchdog system is based on two independent timers providing maximum security to

the applications.

Activation of the watchdog timers is controlled by option bytes or by software. Once activated,

the watchdogs cannot be disabled by the user program without performing a 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. Timeout: At 16 MHz CPU clock the time-out period can be adjusted between 75 µs up to

64 ms.

2. Refresh out of window: The downcounter is refreshed before its value is lower than the

one stored in the window register.

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 wakeup counter

4.8

• Used for auto wakeup from active halt mode

• Clock source: Internal 128 kHz internal low frequency RC oscillator or external clock

• LSI clock can be internally connected to TIM3 input capture channel 1 for calibration

Beeper

4.9

The beeper function outputs a signal on the BEEP pin for sound generation. The signal is in

the range of 1, 2 or 4 kHz.

The beeper output port is only available through the alternate function remap option bit AFR7.

DocID022186 Rev 3

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STM8S005C6T6 Datasheet(PDF) 14 Page - STMicroelectronics