ASQ
(Acquisition
Sequencer)
USS_PWRREQ
00
01
10
11
UUPSCTL.
USSPWRUP
External Signal
PSQ_STOP
UUPSCTL.
ASQEN
ASQ_PDREQ
UUPSCTL.
USSPWRDN
ASQ_STDBYREQ
UUPSCTL.
USSPWRUPSEL
2
ASQ_ACQDONE
PSQ_START
USPSCTL.
USSST
OP
External Signal
External Signal
PSQ
(Power Sequencer)
ASQ_LPBE
UUPSCTL.
USSSWRST
Interface to the ASQ (Acquisition Sequencer)
463
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
Universal USS Power Supply (UUPS)
Table 19-3. Device Power Modes and USS Power
States
USS Power State Change
Device Power Mode
READY
LPM0 or higher
STANDBY
LPM3 or higher
(PMMREGOFF = 0)
19.4 Interface to the ASQ (Acquisition Sequencer)
shows the interface signals between the PSQ and the ASQ (see
for details).
Figure 19-4. USS Power Control
NOTE:
The control signals in
are internal only, and cannot be read or written by user
software.
Table 19-4. Internal Control Signals
Control Signal
Description
Condition to be Triggered
USS_PWRREQ
PSQ to power up the USS module and generate
PSQ_START to the ASQ if UUPSCTL.ASQEN = 1
Trigger one of the sources selected by
UUPSCTL.USSPWRUPSEL
PSQ_START
ASQ to start a new measurement process if
SAPHASCTL0.TRIGSEL = 1
UUPSCTL.UPSTATE = 0
→
2
→
3 and
UUPSCTL.ASQEN = 1
PSQ_STOP
ASQ to stop the current measurement process
UUPSCTL.USSSTOP = 0
→
1
ASQ_ACQDONE
Acknowledge PSQ that ASQ has completed the
measurements
The measurements have been completed
ASQ_STDBYREQ
PSQ to enter STANDBY state
The measurements have been completed and
SAPHASCTL1.ESOFF = 1 and
SAPHASCTL1.STDBY = 1
ASQ_PDREQ
PSQ to power off the USS module
The measurements have been completed and
SAPHASCTL1.ESOFF = 1 and
SAPHASCTL1.STDBY = 0
19.4.1 Start New Measurements
If UUPSCTL.ASQEN = 1, the PSQ block automatically sends the PSQ_START signal to the ASQ when
the USS module is fully powered up. The ASQ starts new measurement sequences upon receiving the
PSQ_START signal if SAPHASCTL0.TRIGSEL = 1. In this case, the full measurement sequence can be
performed without any CPU intervention, and the USS_PWRREQ is the only trigger signal the USS
module needs externally. The PSQ and ASQ must be configured independently (see
). The
ASQ can be triggered by user software by writing SAPHASQTRIG.ASQTRIG = 1 when
SAPHASCTL0.TRIGSEL = 0.