26.8.2.2 Stop mode operation
Depending on clock restrictions related to the MCU core or core peripherals, the MCU is
brought out of stop when a compare event occurs and the corresponding interrupt is
enabled. Similarly, if CR1[OPE] is enabled, the comparator output operates as in the
normal operating mode and comparator output is placed onto the external pin. In Stop
modes, the comparator can be operational in both:
• High-Speed (HS) Comparison mode when CR1[PMODE] = 1
• Low-Speed (LS) Comparison mode when CR1[PMODE] = 0
It is recommended to use the LS mode to minimize power consumption.
If stop is exited with a reset, all comparator registers are put into their reset state.
26.8.2.3 Background Debug Mode Operation
When the microcontroller is in active background debug mode, the CMP continues to
operate normally.
26.8.3 Startup and operation
A typical startup sequence is as follows.
The time required to stabilize COUT will be the power-on delay of the comparators plus
the largest propagation delay from a selected analog source through the analog
comparator, windowing function and filter. See the Data Sheets for power-on delays of
the comparators. The windowing function has a maximum of one bus clock period delay.
The filter delay is specified in the
.
During operation, the propagation delay of the selected data paths must always be
considered. It may take many bus clock cycles for COUT and SCR[CFR]/SCR[CFF] to
reflect an input change or a configuration change to one of the components involved in
the data path.
When programmed for filtering modes, COUT will initially be equal to 0, until sufficient
clock cycles have elapsed to fill all stages of the filter. This occurs even if COUTA is at a
logic 1.
Chapter 26 Comparator (CMP)
KL02 Sub-Family Reference Manual, Rev. 2.1, July 2013
Freescale Semiconductor, Inc.
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