Cypress S6J3200 Series, Manual

Page: 265 / 1355

CHAPTER 15:12-/10-/8-bit Analog to Digital Converter
264 S6J3200 Series Hardware Manual Document Number: 002-04852 Rev. *G
d) In this case first three logical channels are set to trigger type 2 and since there will be no event of
preceding channel conversion completion, the logical channels 0, 1 and 2 will never be converted.
Between the different groups (the group 1, the group 2): the priority of all the logical channels should be
configured as [the group 1 > the group 2] or [the group 1 < the group 2].
(Example: When the priorities of all the channels included in the group 1 are set as 7-9, all the channels of
the group 2 should be set lower (or higher) than 7-9.)
After a group processing is started (at least the conversion of the first channel of the group is started), it
can be interrupted.
Forced stop mode is enabled (ADC12Bn_CTRL.FSMD = "1"): If the triggered channel is higher priority
than the current channel in the group, current conversion of group processing is interrupted after interrupt
operation and the conversion of the channel with the higher priority is started.
Forced stop mode is disabled (ADC12Bn_CTRL.FSMD = "0"): If an A/D conversion is already started, it
cannot be stopped. Hence if the triggered channel is higher priority than the next channel in the group, the
group processing is interrupted before the conversion start of the next logical channel in the group.
The configuration bit fields ADC12B_CHCTRL0 to 63.RSMRST define how the group processing is to be
continued after the higher priority conversion requests are executed. Note that RSMRST setting of the
first channel in the group does not matter, since the group cannot be interrupted before the conversion of
its first channel started.
If stop group setting (RSMRST[1:0] = "00") is configured for a logical channel and the group is interrupted
just before conversion start of that channel, the current processing of the group is stopped. Consequently,
the trigger status flag of the logical channel (set by the conversion completion of the preceding channel in
the group) is cleared.
Figure 3-5 shows an example of stopping a group processing.
(1) Logic channel 0 trigger is issued and processing of the group 0 is initiated.
(2) Processing of the group 0, conversion of logical channels 0 -> 1 -> 2 -> start of channel 3 conversion.
(3) Logic channel 6 trigger is issued during the conversion of channel 3.
(4) The operation is dependent on the setting of forced stop mode (ADC12Bn_CTRL.FSMD).
Forced stop mode is enabled (ADC12Bn_CTRL.FSMD = "1"):
Since the priority of the channel 6 is higher than priority of the channel 3, the processing of the group 0 is
interrupted during the conversion of channel 3. After interrupted operation, processing continues with the
conversion of the channel 6.
Forced stop mode is disabled (ADC12Bn_CTRL.FSMD = "0"):
Since the priority of the channel 6 is higher than priority of the channel 4, the processing of the group 0 is
interrupted after the conversion of channel 3 is finished. Moreover, the trigger status flag of the channel 4
is cleared and processing continues with the conversion of the channel 6.
(5) Group 1 is converted.
(6) Idle trigger group 2 is converted. Group 0 will not be processed until next channel 0 trigger appears.