if use looping, how to interrupt out to next mode?

[TBen.1]

Three mode:

Mode 0: Off

Mode 1: 80% loading (PWM)

Mode 2: 50% loading (PWM)

Frequency: 10KHz

Cycling mode (push button):

Mode 0 -> Mode 1 -> Mode 2 -> Mode 0 -> …. -> ….

When push the button, it will change the next mode immediately.

If I use the delay loop in each mode, it cannot jump to next mode immediately.

How can I do?

[Tesla DeLorean]

Decimate the delay and check the button more frequently, and exit the delay promptly when needed.​