Heat, clock scew and frequency optimization are some of the problems a semiconductor designer must face. By splitting a synchrounous block into multiple pieces which comunicates asynchronously with eachother and provide them with independent clocks, these problems may be reduced. GALS (Global Asynchronous Local Synchronous) is a wrapper that wraps a synchronous block and provides it with a clock. Multiple GALS-elements will make the whole system. The clockfrequency may be independently adjusted between each block.