SDHSCTL4.SDHSON
SDHSCTL5.SSTART
0
1
CONVERSION_START/STOP
SDHSCTL0.
AUTOSSDIS
ASQ_ACQARM (from ASQ)
SDHSCTL0.
TRGSRC
0
1
SDHS_PWR_UP/DOWN
SDHSCTL3.
TRIGEN
ASQ_ACQTRG (from ASQ)
SDHS
AUTO_START
SDHS Functional Operation
582
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
Sigma-Delta High Speed (SDHS)
22.2.6 SDHS Power and Conversion Control
The SDHS has two trigger sources for power and conversion.
shows the connections of the
power and conversion trigger signals to the SDHS.
lists the use cases of the trigger signals.
Figure 22-16. SDHS Power and Conversion Trigger Source
Table 22-3. Control Signals for Power and Conversion
SDHSCTL3.TRI
GEN
SDHSCTL0.TRG
SRC
SDHSCTL0.AUT
OSSDIS
Trigger Signal
Power Up
Power Down
Conversion
Start
Conversion
Stop
1
0
0
SDHSCTL4.SDH
SON = 0
→
1
SDHSCTL4.SDH
SON = 1
→
0
Start
automatically
after power up
See
1
0
1
SDHSCTL4.SDH
SON = 0
→
1
SDHSCTL4.SDH
SON = 1
→
0
SDHSCTL5.SST
ART = 0
→
1
See
1
1
0
Not supported
Not supported
Not supported
Not supported
1
1
1
ASQ_ACQARM
= 0
→
1 (from
ASQ)
ASQ_ACQARM
= 1
→
0 (from
ASQ)
ASQ_ACQTRIG
= 0
→
1 (from
ASQ)
See
0
x
x
Not supported
Not supported
Not supported
Not supported
22.2.6.1 SDHS in Auto Mode and Register Mode
The SDHS is one of the submodules in the USS module. The USS module is designed for ADC-based
ultrasonic sensing technology in various measurement applications. The USS module has its own power
module (see
) to provide the required voltages to the USS submodules including the SDHS. The
USS module support two control modes, register mode and auto mode. In the register mode, the SDHS is
controlled by its own registers. In the auto mode, the SDHS is controlled by the ASQ. See
and
for details.
Table 22-4. USS Auto Mode and Register Mode
USS Control Mode
Configuration for SDHS
Control by: SDHS Power up
Control by: SDHS
Conversion Start
Register
SDHSCTL0.TRGSRC = 0
SDHSCTL4.SDHSON
SDHSCTL5.SSTART
Auto
SDHSCTL0.TRGSRC = 1
ASQ (ASQ_ACQARM signal)
ASQ (ASQ_ACQTRIG signal)