Asynchronous Counter

Hi All,

I have some questions regarding the Asynchronous Counter, let say I need to design an Asynchrouns counter which count from 0 to 1 to 2 to 3 to 5 to 6 then back to 0, what should I do?

I know that for the MOD N counter, I can used NAND get to connect with Asynchronous CLEAR input so that the bit which is not in the state transition will be returned to zero.

I have some doubt on above question on how to CLEAR 4 but back to 5?

I only know how to build the synchronous counter based on the above question but don't know how to build asynchronous counter.

Please advice,

Thanks & Best Regards,
Micheal