30.4.6 Functionality in debug and low-power modes
By default, the watchdog is not functional in Debug mode, Wait mode, or Stop mode.
However, the watchdog can remain functional in these modes as follows:
• For Debug mode, set CS[DBG]. (This way the watchdog is functional in Debug
mode even when the CPU is held by the Debug module.)
• For Wait mode, set CS[WAIT].
• For Stop mode, set CS[STOP], CS[WAIT], and ensure the clock source is active in
STOP mode.
NOTE
For Debug mode and Stop mode, in addition to the above
configurations, a clock source other than the bus clock must be
used as the reference clock for the counter; otherwise, the
watchdog cannot function.
30.4.7 Fast testing of the watchdog
Before executing application code in safety critical applications, users are required to test
that the watchdog works as expected and resets the MCU. Testing every bit of a 16-bit
counter by letting it run to the overflow value takes a relatively long time (64 kHz
clocks).
To help minimize the startup delay for application code after reset, the watchdog has a
feature to test the watchdog more quickly by splitting the counter into its constituent
byte-wide stages. The low and high bytes are run independently and tested for timeout
against the corresponding byte of the timeout value register. (For complete coverage
when testing the high byte of the counter, the test feature feeds the input clock via the 8th
bit of the low byte, thus ensuring that the overflow connection from the low byte to the
high byte is tested.)
Using this test feature reduces the test time to 512 clocks (not including overhead, such as
user configuration and reset vector fetches). To further speed testing, use a faster clock
(such as the bus clock) for the counter reference.
On a power-on reset, the POR bit in the system reset register is set, indicating the user
should perform the WDOG fast test.
Configuring the Watchdog
Kinetis KE1xF Sub-Family Reference Manual, Rev. 4, 06/2019
720
NXP Semiconductors
Содержание KE1xF Series
Страница 2: ...Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 2 NXP Semiconductors...
Страница 60: ...SysTick Clock Configuration Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 60 NXP Semiconductors...
Страница 114: ...Initialization application information Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 114 NXP Semiconductors...
Страница 138: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 138 NXP Semiconductors...
Страница 320: ...Private Peripheral Bus PPB memory map Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 320 NXP Semiconductors...
Страница 342: ...Functional Description Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 342 NXP Semiconductors...
Страница 360: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 360 NXP Semiconductors...
Страница 490: ...Interrupts Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 490 NXP Semiconductors...
Страница 550: ...Memory map and register definition Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 550 NXP Semiconductors...
Страница 562: ...Boot Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 562 NXP Semiconductors...
Страница 662: ...Power supply supervisor Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 662 NXP Semiconductors...
Страница 694: ...On chip resource access control mechanism Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 694 NXP Semiconductors...
Страница 706: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 706 NXP Semiconductors...
Страница 724: ...Application Information Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 724 NXP Semiconductors...
Страница 736: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 736 NXP Semiconductors...
Страница 750: ...Debug and Security Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 750 NXP Semiconductors...
Страница 798: ...Functional description Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 798 NXP Semiconductors...
Страница 808: ...Functional description Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 808 NXP Semiconductors...
Страница 866: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 866 NXP Semiconductors...
Страница 1164: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 1164 NXP Semiconductors...
Страница 1178: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 1178 NXP Semiconductors...
Страница 1380: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 1380 NXP Semiconductors...
Страница 1472: ...Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 1472 NXP Semiconductors...
Страница 1482: ...Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 1482 NXP Semiconductors...