The TPS99000-Q1 operates from two primary clock sources: an internal low frequency oscillator (2 MHz, used for system initialization and other maintenance purposes), and an external high speed (30 MHz) clock, SEQ_CLK, used for most timing critical applications, such as the logic inside the illumination control block and ADC. The TPS99000-Q1 includes a function that reports the ratio of this internal vs. external clock. This ratio is available over the SPI bus. The DLPC23x-Q1 can check this ratio and compare to expected value. If the ratio is incorrect, there is a possibility the DLPC23x-Q1 oscillator may have locked to an incorrect harmonic, or some other fault condition has occurred.