Hardware Interlock Using MAX6369

[kc3ase]

I have some hardware which needs to be interlocked to software such that when there's no watchdog input pulse the hardware circuits become disabled. The MAX6369 has adjustable watchdog times and the 13-30s range is appropriate for the timing.

What I need to do is when WDO goes low for 100mS indicating the detection of lost pulses for 13-30 seconds I have to latch this. The output latch needs to stay low until no WDO pulses are received for over 30 seconds in which case then the output latch could then again go high enabling the hardware circuits.

What is the recommended way of going about this? I was also thinking of just using a window comparator with a cap for pulse detection or maybe a missing pulse detector 555 circuit but these seem to require more external components.

I was thinking of a flip flop on the output of the watchdog but because I only have one pulse for data in I'd need a clock signal that lags slightly behind when the WDO output gets set low.

Any ideas?