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Table 24-9. EWM Refresh Mechanisms
Condition
Mechanism
A unique EWM service occurs when CMPL
< Counter < CMPH.
The software behaves as expected and the counter of the EWM is reset to zero,
and EWM_out pin remains in the deasserted state.
Note: EWM_in pin is also assumed to be in the deasserted state.
A unique EWM service occurs when
Counter < CMPL
The software services the EWM and therefore resets the counter to zero and
asserts the EWM_out pin (irrespective of the EWM_in pin). The EWM_out pin is
expected to gate critical safety circuits.
Counter value reaches CMPH prior to a
unique EWM service
The counter value reaches the CMPH value and no service of the EWM resets
the counter to zero and assert the EWM_out pin (irrespective of the EWM_in
pin). The EWM_out pin is expected to gate critical safety circuits.
Any illegal service on EWM has no effect on EWM_out.
24.5.6 EWM Interrupt
When EWM_out is asserted, an interrupt request is generated to indicate the assertion of
the EWM reset out signal. This interrupt is enabled when CTRL[INTEN] is set. Clearing
this bit clears the interrupt request but does not affect EWM_out. The EWM_out signal
can be deasserted only by forcing a system reset.
Functional Description
KV4x Reference Manual, Rev. 2, 02/2015
460
Preliminary
Freescale Semiconductor, Inc.
Summary of Contents for freescale KV4 Series
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