I am designing a circuit where a negative voltage signal can have multiple levels, eg -12, -8, -6 depending on the circuit state. 

I am looking at several switch detect ICs such as TI's TIC12400 that seems to work with -40V up to +60V on its inputs.

How do I set up a switch detect IC such as TI's TIC12400 or NXP's CD1020 or CD1030 to generate an interrupt whenever my signal changes its voltage, eg from -12 to -8 or from -8 to -6? Is this even possible without additional op-amps/comparators?

TIC12400 datasheet: https://www.ti.com/lit/ds/symlink/tic12400-q1.pdf?ts=1611867637102&ref_url=https%253A%252F%252Fwww.google.com.tr%252F

CD1020 datasheet: https://www.nxp.com/docs/en/data-sheet/CD1020.pdf