ST7260XX datasheet(45/139 Pages) STMICROELECTRONICS

Part #	ST7260XX

Description	Low speed USB 8-bit MCU family with up to 8K Flash

PDF	139 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

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ST7260xx

Watchdog timer (WDG)

45/139

Figure 23.

Watchdog block diagram

Note:

Following a reset, the watchdog is disabled. Once activated it cannot be disabled, except by

a reset.

The T6 bit can be used to generate a software reset (the WDGA bit is set and the T6 bit is

cleared).

12.3.1

Software watchdog option

If Software Watchdog is selected by option byte, the watchdog is disabled following a reset.

Once activated it cannot be disabled, except by a reset.

The T6 bit can be used to generate a software reset (the WDGA bit is set and the T6 bit is

cleared).

12.3.2

Hardware watchdog option

If Hardware Watchdog is selected by option byte, the watchdog is always active and the

WDGA bit in the CR is not used.

Table 23.

Watchdog timing (fCPU = 8 MHz)

CR register initial value

WDG timeout period (ms)

Max

FFh

393.216

Min

C0h

6.144

RESET

WDGA

7-BIT DOWNCOUNTER

fCPU

CLOCK DIVIDER

WATCHDOG CONTROL REGISTER (CR)

÷49152

ST7260XX Datasheet(PDF) 45 Page - STMicroelectronics