Application Note
7 of 33
002-33887 Rev. *A
2022-05-25
Using the Watchdog Timer in XMC7000 family MCUs
Basic WDT
The example shows the following three scenarios:
•
Service the basic WDT counter before it reaches the WARN_LIMIT.
•
Service the basic WDT counter within the pre-warning ISR.
•
If the basic WDT counter is not serviced in time, a RESET is issued after 1 second.
2.6
Window mode
XMC7000 MCUs support the option to define a lower counter threshold that allows a WDT window mode. WDT
window mode supports the observation of two counter limits: a lower limit and an upper limit. If the watchdog
is serviced before the counter has reached the configured lower limit value in the LOWER_LIMIT register, a reset
is issued. If the watchdog is not serviced before the upper limit of the basic WDT counter is reached, a reset is
issued. The two limits define the window timing within which the basic watchdog timer must be serviced. To
enable this function, the LOWER_ACTION[0] bit in the CONFIG register must be set to ‘1’
, and an adequate lower
limit period must be defined in the LOWER_LIMIT register.
The following example calculates the LOWER_LIMIT of 150 ms:
𝐿𝑂𝑊𝐸𝑅_𝐿𝐼𝑀𝐼𝑇 = 32.768
𝑘𝐻𝑧 × 150
𝑚𝑠 = 4915 = 0𝑥00000𝐶𝐶𝐶
2.7
Basic WDT settings
This section describes how to configure the WDT based on a use case using the
ModusToolbox™
CAT1
Peripheral Driver Library provided by Infineon. The code snippets in this application note are part of the
ModusToolbox™
CAT1 Peripheral Driver Library. See
ModusToolbox™
CAT1 Peripheral Driver Library has a configuration part and a driver part. The configuration
part configures the parameter values for the desired operation.