What techniques are used for designing high-speed counters?

High-speed counter techniques: Prescaling (use fast prescaler followed by slower counter), pipelining (register intermediate carries), parallel counting (multiple smaller counters combined), and Gray code (eliminates multi-bit transitions, simplifies synchronization). For GHz operation: minimize combinational logic in carry path, use fast ripple for LSBs with lookahead for MSBs, and optimize flip-flop selection. Synchronous counters with carry lookahead achieve better speed than ripple but require more logic. Implementation must consider clock distribution, hold time margins, and power consumption at high frequencies.