Single-Chip Solution Allows TV, Radio, Digital TV and Broadband Data Capture Over the PCI Bus
Conexant's highly-flexible audio and video broadcast decoder supports all analog broadcast video and audio formats in use worldwide. This single-chip solution enables the host PC to perform audio/video capture, video display, audio playback, or storage and playback at a later time through software or hardware audio/video codecs.
The CX23880/CX23881 is fully compatible with Conexant's family of digital channel demodulators for capture of (HDTV) High Definition Television and Standard Definition Television (SDTV) streams, as well as broadband data over terrestrial, satellite or cable links. The CX23880 interfaces directly to the CX23490 HDTV hardware decoder for offloading the CPU of high-level MPEG-2 decoding tasks.
· 10-bit video decoder· Adaptive comb filter· Global broadcast audio decoder· Stereo DACs· I2S input and output· DTV and broadband support· MPEG encoder and decoder interfaces
A variety of third-party peripheral connectivity options are supported by the CX23880/CX23881. Its General Purpose Input/ Output pins and CPU host port interface enable vendor-specific board functionality and marketplace differentiation.
The CX23880/CX23881 video and broadcast audio capture chip is a mixed-signal monolithic ic enabling a new platform for video, audio, and data communications in the PC. The CX23880/CX23881 chips are designed to offer higher integration, functionality and are significantly more flexible and configurable than the previous generation FusionTM 878A.
CX23880 Overview The CX23880 is designed to offer global support for all analog video broadcast standards in addition to digital broadcasts via an external channel demodulator. It is also designed to offload the CPU of decoding tasks for High Level MPEG-2 (HDTV), 4:2:2 de-interlacing and progressive-scan DVD via a dedicated ViP 2 Host Port interface to the CX23490 high-level MPEG-2 Decoder. CX23881 Overview The a 100% pin-compatible and softwarecompatible subset of the It is particularly suited to the European marketplace and therefore does not support BTSC-dBX and EIAJ audio as broadcast in the U.S. and Japan. In addition, the ViP host port is not supported on the CX23881 as there is no requirement for supporting high-level MPEG-2 decoding for digital television applications. Main Analog Video Capture Overview The CX23880/CX23881 integrates a 10-bit NTSC/ PAL/SECAM composite and s-video decoder, image resizer/scaler, Direct Memory Access (DMA) controller and Peripheral Component Interface (PCI) bus master on a single device. The CX23880/CX23881 can place video data directly into host memory for video capture applications and into a target video display frame buffer for video overlay applications. Both the CX23880 and CX23881 support a general purpose host port for connection to external CODECs for compression of analog video/audio broadcasts that can be stored on the host's hard disk or played back in software. Level MPEG-2 decoding for DVB broadcast applications is supported via a dedicated MPEG port for streaming of compressed data streams to the host for softwarebased decompression.
Video A/Ds Y/C separation Decoded video data output Video data input Broadcast audio Audio input Audio output MPEG data streaming Bi-directional streaming data ports Power supply
8-bit Luma Notch and Chroma Comb Via GPIO Via GPIO BTSC Mono line level I2 S port N/A I2 S port N/A
10-bit Adaptive multi-line 2-D comb filter or 10-bit ITU-R 656 4:2:2 output 8-bit ITU-R 656/VIP 2.0 pixel input BTSC dbx, NICAM, A2, EIAJ, FM Stereo I2 S port Stereo DACs, I2 S port or PCI Bus Dedicated 80 Mbps MPEG port Intel/Motorola host port and VIP 2.0 host master port 3.3/1.8V
10-bit Adaptive multi-line 2-D comb filter or 10-bit ITU-R 656 4:2:2 output 8-bit ITU-R 656/VIP 2.0 pixel input NICAM, A2, FM Stereo I2 S port Stereo DACs, I2 S port or PCI Bus Dedicated 80 Mbps MPEG port Intel/Motorola host port only
As a PCI initiator, the CX23880/CX23881 can take control of the PCI bus to stream data as soon as the bus is available, thereby avoiding the need for on-board frame buffers. The CX23880/CX23881 contains a pixel data First In, First Out (FIFO) to decouple the high-speed PCI bus from the continuous video data stream. The video data input may be scaled, color translated, and burst-transferred to a target location on a field basis. This allows for simultaneous preview of one field and capture of the other field. Alternatively, the CX23880/CX23881 is able to capture or preview both fields simultaneously. The fields may be interlaced into memory or sent to separate field buffers.
Video Input Analog video signals are input to the CX23880/CX23881 via a four-input multiplexer. The multiplexer can select between four composite source inputs or between three composite and a single s-video input source. When an s-video source is input to the CX23880/CX23881, the luma component is fed through the input analog multiplexer, and the chroma component feeds directly into the C-input pin. An Automatic Gain Control (AGC) circuit enables the CX23880/CX23881 to compensate for non-standard amplitudes in the analog signal input.