Interface to the ASQ (Acquisition Sequencer)
464
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
Universal USS Power Supply (UUPS)
shows the interface signals between the PSQ and the ASQ (see
for details). If
UUPSCTL.ASQEN = 1, the PSQ block sends the PSQ_START signal to the ASQ when the USS module
reaches READY state from OFF state. Then, the ASQ starts new measurement sequences upon receiving
the PSQ_START signal if SAPHASCTL0.TRIGSEL = 1. In this case, the full measurement sequences can
be performed without any CPU intervention. The USS_PWRREQ is the only trigger signal the USS needs
to take externally. The PSQ and ASQ must be configured independently (see
). The ASQ can
be triggered manually by user software by writing SAPHASQTRIG.ASQTRIG = 1 when
SAPHASCTL0.TRIGSEL = 0.
Table 19-5. ASQ Trigger
ASQ Auto
Trigger Mode
PSQ Configuration
ASQ Configuration
How to Trigger ASQ
Yes
UUPSCTL.ASQEN = 1
SAPHASCTL0.TRIGSEL = 1
The PSQ sends a trigger signal (PSQ_START) to the
ASQ when the USS gets to READY state
No
UUPSCTL.ASQEN = 0
SAPHASCTL0.TRIGSEL = 1
This configuration is not supported
No
UUPSCTL.ASQEN = 1
SAPHASCTL0.TRIGSEL = 0
The PSQ_START signal generated by the PSQ is
ignored. The ASQ is triggered by writing 1 to
SAPHASQTRIG.ASQTRIG.
No
UUPSCTL.ASQEN = 0
SAPHASCTL0.TRIGSEL = 0
The ASQ is triggered by writing 1 to
SAPHASQTRIG.ASQTRIG.
19.4.2
Stop Measurement Before Completion
While the USS module is performing a measurement, the PSQ can stop the current measurement process
using any of these methods:
•
Write 1 to UUPSCTL.USSSTOP
: The PSQ asserts the PSQ_STOP signal to the ASQ, then the ASQ
starts the process to gracefully stop the current measurement. When the measurement is fully stopped,
the ASQ asserts the ASQ_ACQDONE signal to the PSQ. No changes are made to the USS power
state. The UUPSCTL.USSSTOP bit is cleared when the stop request has been completed. If this bit is
set to 1 when the ASQ is idle, it is cleared immediately.
•
Enable Debug mode
: When debug entry is detected, the PSQ asserts, the PSQ asserts the
PSQ_STOP signal to the ASQ, then the ASQ starts the process to stop the current measurement
gracefully. When the measurement is fully stopped, the ASQ asserts the ASQ_ACQDONE signal to the
PSQ. No changes to the USS power state.
•
Write 1 to UUPSCTL.USSPWRDN
: The PSQ asserts the PSQ_STOP signal to the ASQ, then the
ASQ starts the process to gracefully stop the current measurement. When the measurement is fully
stopped, the ASQ asserts the ASQ_ACQDONE signal, then the PSQ powers off the USS module. The
UUPSCTL.USSPWRDN bit is cleared when the power down request has been completed. If this bit is
set to 1 when the USS module is powered off (OFF state), it is cleared immediately.