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R01UH0336EJ0102 Rev.1.02
Page 390 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 12 Window Watchdog Timer A (WDTA)
12.3.3
Error Detection
The conditions for error detection are:
• Overflow time is exceeded (counter overflow)
• Wrong activation code is written to the trigger register
• Writing to the trigger register outside the open window.
• Illegal update of the watchdog timer mode register (WDTAnMD)
– Writing a new value to WDTAnMD after the first trigger leads to an error
detection.
– Writing the same value to WDTAnMD after the first trigger does not lead
to an error detection.
Error mode
When an error is detected, either an NMI request (WDTAnTNMI) or a reset
(WDTAnTRES) is generated.
WDTAnMD.WDTAnERM selects the error mode:
• WDTAnMD.WDTAnERM = 0: NMI mode
• WDTAnMD.WDTAnERM = 1: Reset mode