CM8888 Datasheet, PDF (4/25 Pages) California Micro Devices Corp – CMOS INTEGRATED DTMF TRANCEIVER

Oxygen^TM Express-series CM8888
High-Performance PCI Express Audio Processor
1 Description and Overview
The Oxygen Express™-series HD CM8888 is a high- quality PCI Express multi-channel audio processor with
an Intel HD Audio specification-compatible audio chip. It is also a controller that can link HDA codecs or
bridge high-quality I2S codecs. The CM8888 can be built into home audio electronics or personal computers
to provide high-fidelity sound, providing a professional audio processing center.
It supports up to 14 outgoing channels and 12 ingoing channels. The 14 outgoing channels are composed of
4 playback DMA’s, including a multi-channel DMA (32 bits, 8 channels, 192k), a S/PDIF & HDMI DMA (each
32 bits, 2 channels, 192k), and a RTC (real-time communication) DMA (32 bits, 2 channels, 192k) channels.
The 12 ingoing channels are spread out in 3 recording DMAs (up to 32 bits, 192k).
The Oxygen Express™-series HD CM8888 is a MCU-based audio processor that can link all the currently
popular codecs, from I2S codecs with over 120dB quality to regular HDA codecs. The audio topology for
HDA specifications is flexible only by changing the firmware. The flexibility to change the firmware gives
customers added flexibility when designing their products. The I2S, HDA-Link, 2-wire master bus, and SPI
interfaces are used to transfer audio data and control data between the CM8888 and codecs. To facilitate
the connection with the existing home audio electronics, the CM8888 has incorporated an S/PDIF
transmitter and receiver with a 192k sampling rate.
A built-in master I2C interface connects to the serial EEPROM to store and retrieve non-evaporable data
for firmware code and the customer applications, including as board configuration, sub-vender and
sub-system IDs, or any dynamic data that customers want to save and restore on system power up.
The Oxygen Express™ HD CM8888 series has an independent 2-wire slave bus to communicate with the MCU.
Strictly speaking, this interface is used as a medium system driver and MCU communication. An MPU-401
MIDI UART is also integrated. There are eight GPI phone jack detect pins, which can be used to distinguish
if a device is plugged into a phone jack. In total there are 10 GPIO pins, however, some of them are shared
with other functions.
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