Note
Asserting more than one hardware trigger select signal
(ADHWTSn) at the same time results in unknown results. To
avoid this, select only one hardware trigger select signal
(ADHWTSn) prior to the next intended conversion.
When the conversion is completed, the result is placed in the Rn registers associated with
the ADHWTSn received. For example:
• ADHWTSA active selects RA register
• ADHWTSn active selects Rn register
The conversion complete flag associated with the ADHWTSn received, that is,
SC1n[COCO], is then set and an interrupt is generated if the respective conversion
complete interrupt has been enabled, that is, SC1[AIEN]=1.
33.4.4 Conversion control
Conversions can be performed as determined by CFG1[MODE] and SC1n[DIFF] as
shown in the description of CFG1[MODE].
Conversions can be initiated by a software or hardware trigger.
In addition, the ADC module can be configured for:
• Low-power operation
• Long sample time
• Continuous conversion
• Hardware average
• Automatic compare of the conversion result to a software determined compare value
33.4.4.1 Initiating conversions
A conversion is initiated:
• Following a write to SC1A, with SC1n[ADCH] not all 1's, if software triggered
operation is selected, that is, when SC2[ADTRG]=0.
• Following a hardware trigger, or ADHWT event, if hardware triggered operation is
selected, that is, SC2[ADTRG]=1, and a hardware trigger select event, ADHWTSn,
has occurred. The channel and status fields selected depend on the active trigger
select signal:
• ADHWTSA active selects SC1A.
Functional description
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
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Freescale Semiconductor, Inc.
