SPRUI33H November 2015 – June 2024 TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1
For diagnostic purposes, the ADC can sample various internal node voltages using a special input selection mux called INTERNALTEST. When internal test mode is enabled, the INTERNALTEST mux selection overrides the ADC-A input channel mux: ADC-A samples the INTERNALTEST selection instead of the channel selected by ADCSOCxCTL.CHSEL. Internal test mode can be used to sample the VDDCORE voltage, VREFLO, VDDA, VSSA, and the CMPSS DAC outputs.
To enable internal test mode, write the desired node selection to the TESTSEL field of the INTERNALTESTCTL analog subsystem register. For safety, INTERNALTESTCTL includes a write key field that must be simultaneously written with the value 0xA5A5 for writes to take effect; otherwise, writes to this register are ignored. For details of internal test mux connections to various internal device voltage nodes, refer to the INTERNALTESTCTL register description.
To disable internal test mode, write 0 to the TESTSEL field of the INTERNALTESTCTL register.
When using internal test mode, the following special considerations apply: