The Oxygen Express™ HD CM8828 is a high quality PCI express multi-channel audio processor that not only an Intel HD Audio specification compatible audio single chip, but also can be a controller which can link HDA codec. CM8828 can be built in the home audio electronics or personal computer to provide high fidelity sound and become a professional audio processing center in your life. It supports up to 10 outgoing channels and 6 ingoing channels. The 10 outgoing channels are composed of 2 playback DMA’s, which are multi-channel DMA (24 bits, 8 channels, 192k), Headphone out & S/PDIF (each 24 bits, 2 channels, 192k), and RTC (real-time communication) DMA (24 bits, 2 channels, 192k). The 6 ingoing channels are spread in 3 recording DMA’s (up to 24 bits, 192k).


  • Compatible with PCI Express 1.1 interface with bus mastering and burst modes


  • Build in HD Audio controller
  • Embedded an 8051-based MCU to transcode HD Audio command to accommodate various external HDA codecs (An external 4 or 8KB serial EEPROM is required]
  • Embedded ROM code for MCU to transcode HD Audio command to control embedded HDA codecs
  • Analog mixer to mix all input data to output streams through HDA codecs

DMA Controller

  • Three playback DMAs and three recording DMAs following Vista/Win7 HD Audio controller requirements and to be WaveRT-port-friendly:
  • Playback DMA#A supports up to 8ch audio output (2,4,6,8CH configurable by SW driver control)
  • Playback DMA#B supports independent 2ch audio output (e.g. Front Headphone Out) or S/PDIF
  • Recording DMA#A supports up to 2ch audio input
  • Recording DMA#B supports independent 2ch audio input
  • Recording DMA#C supports independent 2ch audio input (for S/PDIF input stream or other purpose)
  • Sampling rates: all DMA channels support: 192K/176.4K/96K/88.2K/48K/44.1K PCM data
  • Resolution (Word-length): all DMA channels support: 16/24bit PCM data transfer modes

Audio I/O

  • Intel HD Audio Link supports 1 external HDA codecs
  • Integrated 192K/176.4K/96K/88.2K/48K/44.1K, and 16/24-bit S/PDIF transmitter
  • All input data can be analog mixed to output streams

Control Interface

  • SPI control interfaces
  • I2C Interface supports both Master and Slave mode
  • Interrupt pin for external MCU read transaction
  • Serial EEPROM programming interface for customizing Sub-VendorID/Sub-DeviceID (and even Vendor/Device IDs as well), storing HDA power-on pin configuration (replacing MB BIOS function) and 8051 ROM-codes (HDA command transcoder)
  • Maximum 9 GPIO pins for external devices control and various purposes


  • 24.576MHz crystal input required with embedded PLL for adaptive clock rate
  • Single 3.3V power supply
  • 3.3 V digital I/O pads with 5V tolerance
  • Package and Pin Number: LQFP-80
  • Default target codecs: CM9882A