 Synchronous sequential circuit

A synchronous sequential circuit stores a finite collection of bits $s$, reads inputs $a$, and updates all stored bits at each clock edge according to a specified next-state function $F$. A combinational output is $G(s,a)$; an output that is itself stored is included among the state bits. An initial state is part of a complete design. These equations provide a precise implementation-level description of a finite-state machine without requiring a particular gate drawing.