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Table 18-2. Comparator Sample/Filter Controls (continued)
Mode #
CR1[EN]
CR1[WE]
7
1
All other combinations of CR1[EN], CR1[WE], CR1[SE], CR0[FILTER_CNT], and FPR[FILT_PER] are illegal.
For cases where a comparator is used to drive a fault input (for example, for a motor-
control module such as FTM), it should generally be configured to operate in continuous
mode, so that an external fault can immediately pass through the comparator to the target
fault circuitry.
Filtering and sampling settings should be changed only after
setting CR1[SE]=0 and CR0[FILTER_CNT]=0x00. This has
the effect of resetting the filter to a known state.
18.11.1.1 Disabled Mode (# 1)
In disabled mode, the analog comparator is non-functional and consumes no power. The
output of the analog comparator block (CMPO) is zero in this mode.
18.11.1.2 Continuous Mode (#s 2A & 2B)
NXP Semiconductors
CR0[FILTER_C
CR1[SE]
NT]
1
0
> 0x01
MC9S08SU16 Reference Manual, Rev. 5, 4/2017
Chapter 18 Chip-specific ACMP information
FPR[FILT_PER]
0x01 - 0xFF
Note
Operation
which is then resampled on an
interval determined by FILT_PER to
generate COUT.
Refer to the
Windowed/Resampled
Mode (#
6).
Windowed/Filtered mode
Comparator output is sampled on
every rising bus clock edge when
SAMPLE=1 to generate COUTA,
which is then resampled and filtered
to generate COUT.
Refer to the
Windowed/Filtered
Mode
(#7).
303
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