Interface to the ASQ (Acquisition Sequencer)
465
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
Universal USS Power Supply (UUPS)
19.4.3 USS Power State After Completion of Measurements
The USS power state after completion of the measurement can be programmed to one of the following
states:
•
READY
: No changes to the USS power state. The USS module is ready for the next measurement.
•
STANDBY
: The USS module is powered off but, the SREF block is enabled for fast wakeup.
•
OFF
: The USS module is fully powered off.
lists the configuration to select one of the power states after measurement completion.
Table 19-6. Power States After Measurement
Completion
Configuration Before Starting a
New Measurement
Final USS Power State After
Measurement Completion
SAPHASCTL1.ESOFF = 0
READY
SAPHASCTL1.ESOFF = 1 and
SAPHASCTL1.STDBY = 1
STANDBY
SAPHASCTL1.ESOFF = 1 and
SAPHASCTL1.STDBY = 0
OFF
19.4.4 UUPSCTL.USSPWRUP Bit and UUPSCTL.USS_BUSY Bit
shows that the USS_PWRREQ signal can be generated from a maximum of four different
sources (see the device-specific data sheet for implementation). When UUPSCTL.USSPWRUPSEL = 0,
UUPSCTL.USSPWRUP is selected. In the case, writing 1 to UUPSCTL.USSPWRUP asserts the
USS_PWRREQ signal to the PSQ, then the PSQ starts the power-up sequences, and then the PSQ can
trigger the PSQ to perform new measurements (if UUPSCTL.ASQEN = 1 and
SAPHASCTL0.TRIGSEL = 1). Writing 1 to UUPSCTL.USSPWRUP is invalid and ignored if the power is in
TRANSITION state (UUPSCTL.UPSTATE = 2) or the ASQ is performing a measurement sequence
(UUPSCTL.USS_BUSY = 1), because the current power sequence or the measurement sequence should
be completed before taking a new request.
The UUPSCTL.USS_BUSY bit can be used to monitor the USS module status. When a valid
USS_PWRREQ signal is detected, the PSQ sets the UUPSCTL.USS_BUSY bit to 1 to indicate that the
PSQ is in busy state and is not ready to take a new USS_PWRREQ signal. Do not to generate a new
USS_PWRREQ while UUPSCTL.USS_BUSY = 1. The UUPSCTL.USS_BUSY is set to 1 when any one of
the following conditions is satisfied:
•
UUPSCTL.UPSTATE = 2 (power state = TRANSITION)
•
The ASQ is performing a measurement sequence (the internal signal, ASQ_ACQDONE = 0) .
•
The SDHS is sampling data (SDHSCTL5.SDHS_LCK = 1) even when the measurement is not under
ASQ control (register mode).