ST7263 STMICROELECTRONICS [STMicroelectronics], ST7263 Datasheet - Page 33

• Manufacturer Part Number: ST7263
• Description: LOW SPEED USB 8-BIT MCU FAMILY with up to 16K MEMORY, up to 512 BYTES RAM, 8-BIT ADC, WDG, TIMER, SCI & I2C
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

5.3 WATCHDOG TIMER (WDG)
5.3.1 Introduction
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 T6 bit be-
comes cleared.
Figure 22. Watchdog Block Diagram
f
CPU
WDGA
RESET
T6
T5
WATCHDOG CONTROL REGISTER (CR)
7-BIT DOWNCOUNTER
CLOCK DIVIDER
T4
49152
T3
5.3.2 Main Features
T2
Programmable timer (64 increments of 49152
CPU cycles)
Programmable reset
Reset (if watchdog activated) when the T6 bit
reaches zero
T1
T0
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