Hi Fan,
Watchdog period is selectable between 16ms and 128ms using bits WDPER.
By default WDPER = 0b00, meaning the watchdog period is 16ms and WDMOD = 0b00, meaning watchdog disabled.
Keep in mind that for the first trigger, the watchdog mode is timeout mode with the maximum watchdog nominal period (128ms). Afterwards the watchdog mode and period is according to the watchdog setting.
If the window mode is selected (WDMOD = 0b01), the second and next triggers must happen in the second half of the watchdog period. For WDPER = 0b00 it means between 8ms and 16ms, typically each 12ms.
If the timeout mode is selected (WDMOD = 0b10), the second and next triggers must happen at any time within the watchdog period. For WDPER = 0b00 it means any time within 16ms.
For more information, please refer to our TJA1128 Application Hints, chapter 5.5.4 – Watchdog triggering. Please note that this document is classified as secure file requiring an NDA.
BR, Tomas
