Texas Instruments ADS867 Series Manual page 47

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8.4.2.7 Channel Sequencing Modes
The devices offer two channel sequencing modes: AUTO_RST and MAN_Ch_n.
In AUTO_RST mode, the channel number automatically increments in every subsequent frame. As explained in
the Auto-Scan Sequencing Control Registers
with a register setting. The device automatically scans only the selected analog inputs in ascending order. The
unselected analog input channels can also be powered down for optimizing power consumption in this mode of
operation. The auto-mode sequence can be reset at any time during an automatic scan (using the AUTO_RST
command). When the reset command is received, the ongoing auto-mode sequence is reset and restarts from
the lowest selected channel in the sequence.
In MAN_Ch_n mode, the same input channel is selected during every data conversion frame. The input
command words to select individual analog channels in MAN_Ch_n mode are listed in
input channel is selected during a data frame, then the analog inputs on the same channel are sampled during
the next data frame. Figure 104
MAN_Ch_n mode.
Ch 0
Sample
CS
SCLK
SDI
0000h xxxx
SDO
Ch 0 Data
Figure 104. Transitioning from AUTO_RST to MAN_Ch_n Mode
Figure 105 shows the SDI command sequence for transitions from MAN_Ch_n to AUTO_RST mode. Note that
each SDI command is executed on the next CS falling edge. A RST command can be issued at any instant
during any channel sequencing mode, after which the device is placed into a default power-up state in the next
data frame.
Sample
N
CS
SCLK
SDI
MAN_Ch_2 xxxx
SDO
Sample N Data
Based on Previous
Mode Setting
Figure 105. Transitioning from MAN_Ch_n to AUTO_RST Mode
Copyright © 2015, Texas Instruments Incorporated
section, the analog inputs can be selected for an automatic scan
shows the SDI command sequence for transitions from AUTO_RST to
Ch 5
Sample
MAN_Ch_1
Ch 5 Data
AUTO_RST Mode
(Channels 0 and 5 are Selected for Auto Sequence)
Ch 2
Sample
AUTO_RST
Ch 2 Data
MAN_Ch_n Mode
(Channels 0 and 5 are Selected for Auto Sequence)
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Ch 1
Sample
xxxx MAN_Ch_3
Ch 0
Sample
xxxx 0000h
ADS8674 ADS8678
ADS8674, ADS8678
SBAS627 – JULY 2015
Table 6. If a particular
Ch 3
Sample
xxxx MAN_Ch_n
Ch 1 Data
MAN_Ch_n Mode
Ch 5
Sample
xxxx 0000h
Ch 0 Data
AUTO_RST Mode
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xxxx
Ch 3 Data
xxxx
Ch 5 Data
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