SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
The VTM has 2 reference clock inputs, WKUP_VTM0_FIX_REF_CLK and WKUP_VTM0_FIX_REF2_CLK. The WKUP_VTM0_FIX_REF_CLK is the high precision clock that is used for the sensors. The WKUP_VTM0_FIX_REF2_CLK is a lower precision clock that can be used during low power scenarios to keep the sensors running when the WKUP_VTM0_FIX_REF_CLK is shut off. WKUP_VTM_CLK_CTRL[31] TSENS_CLK_SEL and WKUP_VTM_CLK_CTRL[4-0] TSENS_CLK_DIV are used to switch between the clocks and to choose the divider value. All the sensors in all VDs controlled by this VTM will run off of the same reference clock.
Software must disable all sensors before switching the reference clock.
For more information about propagation sequence of the sensor changes, see Section 5.2.2.2.5.3.7.3, Sensors Programming Sequences.