Datasheet

877
SAM9G15 [DATASHEET]
11052D–ATARM–31-Oct-12
Figure 41-4. GOVRE and OVREx Flag Behavior
Warning: If the corresponding channel is disabled during a conversion or if it is disabled and then reenabled during a
conversion, its associated data and its corresponding EOC and OVRE flags in ADC_SR are unpredictable.
41.6.5 Conversion Triggers
Conversions of the active analog channels are started with a software or hardware trigger. The software trigger is
provided by writing the Control Register (ADC_CR) with the START bit at 1.
The hardware trigger can be selected by the TRGMOD field in the “ADC Trigger Register” between:
z Any edge, either rising or falling or both, detected on the external trigger pin, TSADTRG.
z The Pen Detect, depending on how the PENDET bit is set in the “ADC Touchscreen Mode Register”.
z A continuous trigger, meaning the ADC Controller restarts the next sequence as soon as it finishes the current one
z A periodic trigger, which is defined by programming the TRGPER field in the “ADC Trigger Register”.
The minimum time between 2 consecutive trigger events must be strictly greater than the duration time of the longest
conversion sequence according to configuration of registers ADC_MR, ADC_CHSR, ADC_SEQR1, ADC_SEQR2,
ADC_TSMR.
EOC0
GOVRE
CH0
(ADC_CHSR)
(ADC_SR)
(ADC_SR)
Trigger event
EOC1
CH1
(ADC_CHSR)
(ADC_SR)
OVRE0
(ADC_OVER)
Undefined Data Data A
Data B
ADC_LCDR
Undefined Data
Data A
ADC_CDR0
Undefined Data
Data B
ADC_CDR1
Data C
Data C
Conversion C
Conversion A
DRDY
(ADC_SR)
Read ADC_CDR1
Read ADC_CDR0
Conversion B
Read ADC_OVER
Read ADC_SR
OVRE1
(ADC_OVER)