OH! is an open-source library of hardware building blocks based on silicon proven design practices at 0.35um to 28nm. The library is being used by Adapteva in designing its next generation ASIC. The library is written in standard Verilog (2005) and contains over 25,000 lines of Verilog code, over 150 separate modules. Examples of functionality include: FIFOs, SPI (master/slave), GPIO, high speed links, memories, clock circuits, synchronization primitives,interrupt controller, DMA.