This document introduces the Cirrus Logic CRD4201-2 Advanced Communications Riser (ACR) reference design, which features six channel analog audio outputs and a optical S/PDIF digital output. This board uses the CS4201 audio codec, which has many advanced features such as a built-in headphone amplifier, up to 30 dB of microphone boost and serial digital audio outputs. The reference design is available by ordering the CMK4201-2 manufacturing kit. This kit includes a full set of schematic design files (OrCAD® 7.2 and Or- CAD® 9.1 formats), PCB job files (PADS® ASCII), PCB artwork files and bill of materials. This reference design offers significant cost advantages, as it is based on a 2-layer low cost PC board.