User Manual
378
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
Watchdog Timer (WDT1)
Figure 74 Effective
Open
Window
E.g. for a variation of 20% and a nominal watchdog period of T
WD
the start of the effective open window T
OWmin
is shifted back by 10%, and the end of the effective open window T
OWmax
is shifted forward by 20%.
Short Open Window (SOW)
Under certain programming conditions, e.g. NVM programming, it might be desired to interrupt the normal
windowed watchdog operation. For this purpose a special trigger of a short open window (see
allows to discard the current window period (also within the closed window) and immediately starts a short
open window. The short open window has a fixed length of TSOW independent of the settings of the WDP_SEL
bits.
Figure 75 Short
Open
Window
Minimum Watchdog Period
50% of Watchdog Period
50% of Watchdog Period
Nominal Watchdog Period
Maximum Watchdog Period
Safe Trigger Area
(Effective Open Window)
closed window
open window
closed window
open window
closed window
open window
closed window
open window
T
WD
T
OWmax
T
OWmin
NVM
routine
Software Routine
T
Software Routine
Watchdog operation:
Software tasks:
Software Routine
T
closed window
open window
closed window
Short Open
window
closed window
open window
NVM
routine
Trigger within
open window
Legende:
Trigger of
Short Open Window
T
T
S
T
S
T
S
Short Open
window