Detector of a 1 followed by 1 in a sequence of 0s

Question

I need to design a digital circuit that detects when a sequence of 0s does NOT contain a 1 followed by 1 (or more).

Example:

00000000010001000000000 Output: 1

00000011000000010000000 Output: 0

I know how to design a sequence detector, but this case is a little bit different since it needs to check the whole sequence before giving an output.

Thank you.

Answer 1

Either I am missing something, or this is pretty straightforward. Look at the diagram below. when the second 1 gets clocked in, your output switch to 0, and stays 0 until you reset the circuit for the next sequence. If no double zero appear in the stream, output stays 1.

^{simulate this circuit – Schematic created using CircuitLab}