Simplifying integrated circuits with a common communications bus

When integrating a peripheral, it is common practice to use a fully custom design. Custom designs typically optimize performance, size, and energy usage. However, custom designs are more expensive in terms of testing and development time. Rather than designing an integrated peripheral, an existing design (for example, peripheral 420) for the peripheral with attendant communications bus interface (for example, interface 424) is combined with an existing communications bus interface (for example, peripheral bus interface 410) to produce an integrated circuit (for example, integrated circuit 405). The use of existing designs greatly reduces development and test time, along with costs.