ST6208C/ST6209C/ST6210C/ST6220C
8 ON-CHIP PERIPHERALS
8.1 WATCHDOG TIMER (WDG)
8.1.1 Introduction
8.1.2 Main Features
■ Programmable timer (64 steps of 3072 clock
The Watchdog timer is used to detect the occur-
rence of a software fault, usually generated by ex-
ternal interference or by unforeseen logical condi-
tions, which causes the application program to
abandon its normal sequence. The Watchdog cir-
cuit generates an MCU reset on expiry of a pro-
grammed time period, unless the program refresh-
es the counter’s contents before the SR bit be-
comes cleared.
cycles)
■ Software reset
■ Reset (if watchdog activated) when the SR bit
reaches zero
■ Hardware or software watchdog activation
selectable by option bit (Refer to the option
bytes section)
Figure 25. Watchdog Block Diagram
RESET
WATCHDOG REGISTER (WDGR)
T0
T5
SR
T1
C
T2
T4
T3
bit 7
bit 0
7-BIT DOWNCOUNTER
CLOCK DIVIDER
f
int /12
÷ 256
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STMICROELECTRONICS [ ST ]
