This part is a kind of semiconductor called CM6631A.
Function of this product has USB 2.0 High-Speed True HD Audio Processor.
Manufacturers : C-Media
Image and pinout :

Some of the text within the PDF file :
CM6631A USB 2.0 High-Speed True HD Audio Processor DESCRIPTION Cmedia CM6631A is a USB2.0 true high-speed audio processor that can support the latest USB Audio Device Class Definition V2.0 and high-definition audio processing capability up to 192KHz/32bit. CM6631A provides the industrial standard I2S and HDA audio interface and also integrates 192KHz/24bit S/PDIF transmitter/receiver and MIDI I/O device. It’s suitable for versatile, high-profile, typical 2-channel I/O audio applications. Furthermore, CM6631A has an embedded 8051 microprocessor that can enhance the best flexibility and functionality with external upgradeable F/W codes. CM6631A would be the most high-fidelity and powerful audio core for high-value USB2.0 audio products. BLOCK DIAGRAM Self-Power GPIO/JD FEATURES US [ ... ]
CM6631A PDF Datasheet Download
