L99PM72PXP datasheet(24/128 Pages) STMICROELECTRONICS

Part #	L99PM72PXP

Description	Advanced power management system IC with embedded LIN and high speed CAN transceiver supporting CAN Partial Networking

PDF	128 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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Detailed description

L99PM72PXP

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Doc ID 023553 Rev 3

Figure 9.

Main operating modes

2.4

Configurable window watchdog

During normal operation, the watchdog monitors the micro controller within a programmable

trigger cycle: (10 ms, 50 ms, 100 ms, 200 ms)

In VBat_standby and Flash program modes, the watchdog circuit is automatically disabled. In

V1_standby mode a wake up by timer is programmable in order to wake up the µC (see

Section 2.2.10). After wake-up, the Watchdog starts with a long open window. After serving

the watchdog, the microcontroller may send the device back to V1_standby mode.

After power-on or Standby mode, the watchdog is started with a long open window (65 ms

nominal). The long open window allows the micro controller to run its own setup and then to

trigger the watchdog via the SPI. The trigger is processed when the CSN input becomes

HIGH after the transmission of the SPI word.

Writing '1' to the watchdog trigger bit terminates the long open window and start the window

watchdog (the timing is programmable by SPI). Subsequently, the micro controller has to

L99PM72PXP Datasheet(PDF) 24 Page - STMicroelectronics