5. Confirm the WDOG flag in the system reset register is set, indicating that the
watchdog caused the reset. (The POR flag remains clear.)
6. Confirm that WDOG_CS1[TST] shows a test (10b or 11b) was performed.
If confirmed, the count and compare functions work for the selected byte. Repeat the
procedure, selecting the other byte in step 2.
NOTE
WDOG_CS1[TST] is cleared by a POR only and not affected
by other resets.
17.3.7.2 Entering user mode
After successfully testing the low and high bytes of the watchdog counter, the user can
configure WDOG_CS1[TST] to 01b to indicate the watchdog is ready for use in
application user mode. Thus if a reset occurs again, software can recognize the reset
trigger as a real watchdog reset caused by runaway or faulty application code.
As an ongoing test when using the default 1-kHz clock source, software can periodically
read the WDOG_CNTH and WDOG_CNTL registers to ensure the counter is being
incremented.
Functional description
MC9S08PA4 Reference Manual, Rev. 5, 08/2017
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NXP Semiconductors
Summary of Contents for MC9S08PA4
Page 1: ...MC9S08PA4 Reference Manual Supports MC9S08PA4 Document Number MC9S08PA4RM Rev 5 08 2017 ...
Page 2: ...MC9S08PA4 Reference Manual Rev 5 08 2017 2 NXP Semiconductors ...
Page 22: ...MC9S08PA4 Reference Manual Rev 5 08 2017 22 NXP Semiconductors ...
Page 28: ...System clock distribution MC9S08PA4 Reference Manual Rev 5 08 2017 28 NXP Semiconductors ...
Page 150: ...Port data registers MC9S08PA4 Reference Manual Rev 5 08 2017 150 NXP Semiconductors ...
Page 196: ...Human machine interfaces HMI MC9S08PA4 Reference Manual Rev 5 08 2017 196 NXP Semiconductors ...
Page 224: ...Instruction Set Summary MC9S08PA4 Reference Manual Rev 5 08 2017 224 NXP Semiconductors ...
Page 232: ...Functional Description MC9S08PA4 Reference Manual Rev 5 08 2017 232 NXP Semiconductors ...
Page 258: ...FTM Interrupts MC9S08PA4 Reference Manual Rev 5 08 2017 258 NXP Semiconductors ...
Page 294: ...Functional description MC9S08PA4 Reference Manual Rev 5 08 2017 294 NXP Semiconductors ...
Page 398: ...Resets MC9S08PA4 Reference Manual Rev 5 08 2017 398 NXP Semiconductors ...
Page 400: ...MC9S08PA4 Reference Manual Rev 5 08 2017 400 NXP Semiconductors ...