ST STM32F301 6 Series Reference Manual page 219

RM0366
Note: When writing P3, the context changes immediately. However, because of internal
resynchronization, there is a latency and if a trigger occurs just after or before writing P3, it
can happen that the conversion is launched considering the context P2. To avoid this
situation, the user must ensure that there is no ADC trigger happening when writing a new
context that applies immediately.
Figure 41. Example of JSQR queue of context with empty queue (case JQM=1)
P1
Write JSQR
JSQR queue
EMPTY
Trigger 1
ADC J context
EMPTY
(returned by
reading JSQR)
ADC state
1. Parameters:
P1: sequence of 1 conversion, hardware trigger 1
P2: sequence of 1 conversion, hardware trigger 1
P3: sequence of 1 conversion, hardware trigger 1
Flushing the queue of context
The figures below show the behavior of the context Queue in various situations when the
queue is flushed.
Figure 42. Flushing JSQR queue of context by setting JADSTP=1 (JQM=0).
Write JSQR
JSQR queue
JADSTP
JADSTART
Trigger 1
ADC J context
(returned by reading JSQR)
ADC state
1. Parameters:
P1: sequence of 1 conversion, hardware trigger 1
P2: sequence of 1 conversion, hardware trigger 1
P3: sequence of 1 conversion, hardware trigger 1
Queue becomes empty and triggers are
P2
P1 P1,P2
P1
RDY Conversion1 RDY
Case when JADSTP occurs during an ongoing conversion.
P1 P2
EMPTY P1
EMPTY P1
RDY
RM0366 Rev 5
Analog-to-digital converters (ADC)
ignored because JQM=1
P2 EMPTY
P2 EMPTY (0x0000)
Conversion1
Queue is flushed and maintains
the last active context
(P2 is lost)
P1, P2 P1
Set Reset
by S/W by H/W
Reset
by H/W
P3
P3
Ignored
P3
RDY Conversion1
P3
P3
Set
by S/W
P3
RDY Conversion1
EMPTY
Ignored
EMPTY
RDY
MS30541V2
RDY
MS30544V2
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