Texas Instruments MSP430x4xx - Manual (Page 414)

SD16 Operation
21-11 SD16
Figure 21−6. Single Channel Operation
Channel 0
SD16SNGL = 1
SD16GRP = 0
Time
Conversion
SD16SC
Channel 1
SD16SNGL = 1
SD16GRP = 0
Conversion
Channel 2
SD16SNGL = 0
SD16GRP = 0
Conversion
SD16SC
SD16SC
Conversion Conversion
Conversion
Set by SW Auto−clear
Set by SW Auto−clear Set by SW Auto−clear
Set by SW
Conv
Cleared by SW
= Result written to SD16MEMx
Group of Channels, Single Conversion
Consecutive SD16 channels can be grouped together with the SD16GRP bit
to synchronize conversions. Setting SD16GRP for a channel groups that
channel with the next channel in the module. For example, setting SD16GRP
for channel 0 groups that channel with channel 1. In this case, channel 1 is the
master channel, enabling and disabling conversion of all channels in the group
with its SD16SC bit. The SD16GRP bit of the master channel is always 0. The
SD16GRP bit of last channel in SD16 has no function and is always 0.
When SD16SNGL = 1 for a channel in a group, single conversion mode is
selected. A single conversion of that channel will occur synchronously when
the master channel SD16SC bit is set. The SD16SC bit of all channels in the
group will automatically be set and cleared by SD16SC of the master channel.
SD16SC for each channel can also be cleared in software independently.
Clearing SD16SC of the master channel before the conversions are
completed immediately stops conversions of all channels in the group, the
channels are powered down and the corresponding digital filters are turned off.
Values in SD16MEMx can change when SD16SC is cleared. It is
recommended that the conversion data in SD16MEMx be read prior to
clearing SD16SC to avoid reading an invalid result.