Texas Instruments MSP430x4xx Computer Hardware User Manual


 
SD16 Operation
21-14 SD16
Figure 219. Start of Conversion using Preload
Delayed Conversion
40
SD16OSRx = 32
Start of
Conversion
Time
Conversion
32
Conversion
32f
M
cycles:
1
st
Sample Ch1
SD16PRE0 = 8
SD16PRE1 = 0 Conversion
32
Conversion
32
Conversion
32
Conversion
1
st
Sample Ch0
When channels are grouped, care must be taken when a channel or channels
operate in single conversion mode or are disabled in software while the master
channel remains active. Each time channels in the group are re-enabled and
re-synchronize with the master channel, the preload delay for that channel will
be reintroduced. Figure 2110 shows the re-synchronization and preload
delays for channels in a group. It is recommended that SD16PREx = 0 for the
master channel to maintain a consistent delay between the master and
remaining channels in the group when they are re-enabled.
Figure 2110. Preload and Channel Synchronization
Channel 0
SD16SNGL = 0
SD16GRP = 1
Time
Conversion
SD16SC
Channel 1
SD16SNGL = 1
SD16GRP =1
Conversion
Channel 2
SD16SNGL = 0
SD16GRP = 0
Conversion
SD16SC
SD16SC
Conversion Conversion
Set by Ch2 Autoclear
Set by Ch2
Conv
Set by SW
Conversion
Set by SW Autoclear
(syncronized to master)
Cleared by SW
Conv
Set by SW
(syncronized to master)
= Result written to SD16MEMx
PRE1 PRE1
PRE0
Conversion
PRE0 Conv