US Patent 7305058 Multi-standard clock rate matching circuitry

Clock rate matching circuitry is provided to buffer data between two clock domains that may have slightly different frequencies. To facilitate supporting a wide range of different communication protocols, the clock rate matching circuitry includes dedicated control circuitry and is also associated with other circuitry that is capable of acting as control circuitry that can be used as an alternative to at least part of the dedicated control circuitry. For example, the dedicated control circuitry may be set up to support one or several industry-standard protocols. The other circuitry (which may be, for example, programmable logic circuitry) is available to support any of a wide range of other protocols, whether industry-standard or custom.