CONEXANT CX23880

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PCl Audio/Video
Broadcast Decoder
CX23880/CX23881
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.
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.
Distinguishing Features
• 10-bit video decoder
• Adaptive comb filter
• Global broadcast audio decoder
• Stereo DACs
Functional Overview
• I2S input and output
The CX23880/CX23881 video and broadcast audio capture chip
• DTV and broadband support
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 Fusion™ 878A.
• MPEG encoder and decoder interfaces
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PCl Audio/Video
Broadcast Decoder
CX23880/CX23881
CX23880 Overview
Level MPEG-2 decoding for DVB broadcast applications
The CX23880 is designed to offer global support
is supported via a dedicated MPEG port for streaming
for all analog video broadcast standards in
of compressed data streams to the host for software-
addition to digital broadcasts via an external channel
based decompression.
demodulator. It is also designed to offload the CPU
of decoding tasks for High Level MPEG-2 (HDTV),
Both the CX23880 and CX23881 support a general
4:2:2 de-interlacing and progressive-scan DVD via
purpose host port for connection to external CODECs
a dedicated ViP 2 Host Port interface to the CX23490
for compression of analog video/audio broadcasts
high-level MPEG-2 Decoder.
that can be stored on the host’s hard disk or played
back in software.
CX23881 Overview
The CX23881 is a 100% pin-compatible and software-
Analog Video Capture Overview
compatible subset of the CX23880. It is particularly
The CX23880/CX23881 integrates a 10-bit NTSC/
suited to the European marketplace and therefore
PAL/SECAM composite and s-video decoder, image
does not support BTSC-dBX and EIAJ audio as
resizer/scaler, Direct Memory Access (DMA) controller
broadcast in the U.S. and Japan. In addition, the ViP
and Peripheral Component Interface (PCI) bus
host port is not supported on the CX23881 as there is
master on a single device. The CX23880/CX23881
no requirement for supporting high-level MPEG-2
can place video data directly into host memory for
decoding for digital television applications. Main
video capture applications and into a target video
display frame buffer for video overlay applications.
Fusion 878A
CX23880
CX23881
8-bit
10-bit
10-bit
Luma Notch and Chroma Comb
Adaptive multi-line 2-D comb filter
Adaptive multi-line 2-D comb filter
Decoded video data output
Via GPIO
8- or 10-bit ITU-R 656 4:2:2 output
8- or 10-bit ITU-R 656 4:2:2 output
Video data input
Via GPIO
8-bit ITU-R 656/VIP 2.0 pixel input
8-bit ITU-R 656/VIP 2.0 pixel input
Broadcast audio
BTSC Mono
BTSC dbx, NICAM, A2, EIAJ, FM
NICAM, A2, FM
Mono line level or I2 S port
Stereo I2 S port
Stereo I2 S port
N/A
Stereo DACs, I2 S port or PCI Bus
Stereo DACs, I2 S port or PCI Bus
I2 S port
Dedicated 80 Mbps MPEG port
Dedicated 80 Mbps MPEG port
Bi-directional streaming
data ports
N/A
Intel/Motorola host port
and VIP 2.0 host master port
Intel/Motorola host port only
Power supply
5V
3.3/1.8V
3.3/1.8V
Feature
Video A/Ds
Y/C separation
Audio input
Audio output
MPEG data streaming
CX23880 block diagram
As a PCI initiator, the CX23880/CX23881 can take control
Video Input
of the PCI bus to stream data as soon as the bus is available,
Analog video signals are input to the CX23880/CX23881 via
thereby avoiding the need for on-board frame buffers.
a four-input multiplexer. The multiplexer can select between
The CX23880/CX23881 contains a pixel data First In, First Out
four composite source inputs or between three composite and
(FIFO) to decouple the high-speed PCI bus from the continuous
a single s-video input source. When an s-video source is input
video data stream. The video data input may be scaled, color
to the CX23880/CX23881, the luma component is fed through
translated, and burst-transferred to a target location on a field
the input analog multiplexer, and the chroma component
basis. This allows for simultaneous preview of one field and
feeds directly into the C-input pin. An Automatic Gain Control
capture of the other field. Alternatively, the CX23880/CX23881
(AGC) circuit enables the CX23880/CX23881 to compensate
is able to capture or preview both fields simultaneously.
for non-standard amplitudes in the analog signal input.
The fields may be interlaced into memory or sent to
separate field buffers.
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Reduced Instruction Set Computing (RISC) Engine
frame output mode in which every line in the video frame
The CX23880/CX23881 enables separate destinations for
is treated as if it were a VBI line. This mode of operation is
the odd and even video fields, each controlled by a pixel
designed for use with still-frame capture and processing
RISC instruction list. This instruction list is created by the
applications, where sophisticated image decoding can be
CX23880/CX23881 device driver and may be run in the
performed in the software domain.
on-chip memory or host memory. The instructions control
the transfer of pixels to target memory locations on a byte
Macrovision® Detector
resolution basis. Complex clipping can be accomplished by
With the advent of more powerful CPUs that enable
the instruction list, blocking the generation of PCI bus cycles
software-based video compression, low-cost hardware
for pixels that are not to be seen on the display.
MPEG encoders, cheap and rewritable storage media, and
pervasive broadband communications, original content
The DMA channels can be programmed on a field basis to
protection is paramount. To this end, the CX23880/CX23881
deliver the video data in packed or planar format. In packed
fully implements Macrovision 7.01 detection. When an end-
mode, YCrCb data is stored in a single continuous block of
user attempts to connect a digital video disk (DVD) player,
memory. In planar mode, the YCrCb data is separated into
a digital satellite/cable decoder’s composite, or s-video out-
three streams which are burst to different target memory
puts to the input of a CX23880/ CX23881-based PCI card,
blocks. Having the video data in planar format is useful for
Macrovision pulses and signals are detected, and appropriate
applications where data compression is accomplished via
flag bits are set. It is up to the board vendor to read the flag
software and the CPU.
bits and determine what action will be taken.
UltraLock™
Analog Audio Capture
The CX23880/CX23881 employs a proprietary technique
The CX23880/CX23881 captures and decodes all major
known as UltraLock to lock on to the incoming analog video
terrestrial broadcast audio standards. The CX23880/CX23881
signal. It consistently generates the required number of
digitizes and oversamples the low intermediate frequency
pixels per line from an analog source in which line length
(IF) signal from a TV tuner, and extracts and decodes the
can vary by as much as a few microseconds. UltraLock’s
broadcast audio signal. The decoded audio is sample rate
digital locking circuitry enables the CX23880/CX23881 to
converted to a 48 KHz pulse code modulation (PCM) stereo
lock onto video signals quickly and accurately, regardless
signal to simplify processing and interfacing. This 48 KHz
of their source. The technique is completely digital, so
stream can be routed to the built-in (90 dB Signal-to-Noise
UltraLock can recognize unstable signals caused by
Ratio (SNR) stereo audio Digital-to-Analog Converters
VCR head switches or any other deviation and can adapt
(DACs) for connection to the PC’s sound card or headphones,
the locking mechanism to accommodate the source.
to an external Digital-Audio Interface, or to the PCI bus and
UltraLock uses nonlinear techniques that are difficult,
host for direct capture by a software audio codec. The
if not impossible, to implement in genlock systems.
CX23881 only supports NICAM, A2 and FM broadcast audio
Unlike linear techniques, it adapts the locking mechanism
standards primarily for the European marketplace.
automatically.
If capture of line-level stereo audio signals is required, an
Vertical Blanking Interval (VBI) Data Capture
inexpensive audio analog-to-digital converter A/D may
The CX23880/CX23881 provides a flexible solution for
be directly connected to the CX23880/CX23881’s I 2S input
capturing and decoding disparate VBI data types such as
port and controlled via the serial bus master.
closed-caption data, teletext, vertical internal time and
control (VITC) codes, HTML data, or multicast data. The
CX23880/CX23881 can operate in a VBI line output mode,
in which the VBI data is only captured from selected lines.
This mode of operation enables concurrent capture of VBI
lines containing ancillary data and normal video image
data. In addition, the CX23880/CX23881 supports a VBI
ITU-R 656 4:2:2 Data Output
What is a Broadcast Decoder?
The CX23880/CX23881 provides a 27 MHz, 8- or 10-bit
ITU-R 656 decoded video output interface to allow
connection of a third-party MPEG-2 encoder or other type
A broadcast decoder is designed to capture and decode the
video and audio portions of any analog TV broadcast
of video codec. This is useful when the host CPU is not
powerful enough to perform such tasks in software, or
signal. In addition, a broadcast decoder must be able to
when high-quality encoding must be achieved. Please
contact Conexant Application Engineering for a list of
supported third-party video compressors.
ITU-R 656/VIP 2.0 Pixel Data Input
address the transition to all-digital broadcasting by offering
a variety of methods to connect to digital TV channel
demodulators. Sufficient I/O must be provided to support
The CX23880/CX23881 provides a 27 MHz, 8-bit ITU-R 656
decoded video input interface to allow a third-party MPEG-2
decoder or codec to send 4:2:2 data over the PCI bus to
external hardware-based compression of analog video/audio
signals in order to enable storage onto hard disks or CDROM.
a target video display frame buffer for video overlay.
Alternatively, 480-line progressive scan video from the
CX23490 all-format MPEG-2 decoder may be input to this
port using Video Interface Port (VIP) 2.0-compliant pixel
timing at up to 54 MHz.
Conexant’s broadcast decoder meets these objectives
in the following way:
1) It captures and decodes all variations of NTSC, PAL
Antenna
Ant1
and SECAM video standards into digital RGB or YUV
Tuner
Ant2
CVBS
C
Composite or
S-Video In
Stereo
Audio Out
Serial Data
pixel streams.
2nd IF
Cable
Y
Serial Bus
2) It captures and decodes all broadcast audio standards
used worldwide such as BTSC/DBX, NICAM, A2, EIAJ
C
Y
and FM/AM, into 48 KHz PCM streams or stereo left
L
and right audio signals.
R
3) It facilitates “analog to MPEG” conversion by providing
an 8- or 10-bit ITU-R 656 pixel interface to an external
MPEG 2 encoder for real-time compression. Providing
PCI BUS
a streaming host port or MPEG port for DMA of
compressed data to the host or hard disk.
TV/FM block diagram
4) It provides a dedicated high-speed streaming MPEG
TV/FM application example
Features:
• Single-chip capture/record of broadcast TV and radio to PC
port that is compatible with ATSC, DVB and ISDB digital
television channel demodulators for DMA to the host
• Global video standards support
• Global audio standards support including FM/AM radio
• Many I/O ports to differentiate design
or hard disk.
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MPEG Data Port
GPIO Port
Channel demodulators used for digital TV or broadband
The CX23880/CX23881 provides up to 24 GPIO pins. These
data applications over terrestrial, satellite, or cable
GPIO pins are shared with the following pins/ports groups
networks may be directly connected to the CX23880/CX23881’s
so that the user can determine exactly which pins can be
MPEG data port to deliver transport streams to the host for
dedicated to specific functions versus GPIO functions:
subsequent storage to disk or software decode. Either parallel
• MPEG parallel data port
Digital Video Broadcasting (DVB) (common interface) or
• ITU–R 656 4:2:2 data output
serial data paths from the channel demodulator may be
• ITU–R 656 4:2:2 data input
supported at data transfer rates of up to 80 Mbps. If the
• Extended VIP host port
serial interface mode is used, then the remaining unused
pins on this port may be allocated as GPIO.
Serial Bus Interface
The CX23880/CX23881’s serial bus interface supports both
VIP 2.0 Host-Master Interface Port (CX23880 only)
99.2 KHz timing transactions and 396.8 kHz, repeated start,
The VIP 2.0 host-master interface allows the CX23880 to
multibyte sequential transactions. As a serial bus master,
communicate with all devices that are compliant with the
the CX23880/CX23881 can program other devices on the
VIP slave specification. This implementation of a VIP 2.0
video card, such as a TV tuner, as long as the device
master is backwards-compatible with all VIP 1.1-compliant
address is known. The CX23880/CX23881 supports
slave interfaces. The CX23880 is designed to connect to the
multibyte sequential reads (more than one transaction)
CX23490 all-format MPEG-2 decoder via this interface. The
and multibyte write transactions (greater than three
functionality of the VIP host-master interface is threefold.
transactions), which enable communication to devices
The first concept is to stream data from a VIP slave into
that support auto-incremental internal addressing.
host memory via the PCI bus. The second concept is to
stream out data to a VIP slave that is sent over the PCI bus
PCI Bus Interface
from the host. The third concept is for the host to be able
The CX23880/CX23881 is designed to efficiently utilize the
to access register space on connected VIP slave devices.
available 132 Mbps PCI bus. The 32-bit words are output
The CX23881 does not support the VIP 2.0 host master
on the PCI bus with the appropriate image data under the
interface port and in order to retain pin compatability with
control of the DMA channels. The video stream consumes
the CX23880, these pins are configured as GPIO.
bus bandwidth with average data rates varying from 44
Mbps for full-size 768 x 576 PAL RGB32, to 4.6 Mbps for
General Purpose Host Interface Port
NTSC CIF 320 x 240 RGB16, to 0.14 Mbps for NTSC ICON
The general purpose host interface allows the
80 x 60 8-bit mode.
connection of moderate to relatively slow-speed third-party
peripherals (such as infrared remote control processors,
The pixel instruction stream for the DMA channels
codec host ports, smart card controllers, etc.), to the
consumes a minimum of 0.1 Mbps. The CX23880/CX23881
CX23880/CX23881. This port allows simultaneous
provides the means for handling the bandwidth bottle-
connection to two peripherals glue free, or as many as
necks caused by slow targets and long bus access
four peripherals with the use of external glue logic to
latencies that can occur in some system configurations.
provide the additional chip selects. This interface may have
To overcome these system bottlenecks, the CX23880
one upstream and one downstream DMA channel active
gracefully degrades and recovers from FIFO overruns
to or from the external peripherals at any given time.
to the nearest pixel in real time.
SPDIF
Driver
TS OUT
656 IN
VIP_HOST
MPEG
C
Composite or
S-Video In
656 Out
Y Serial Bus
C
Mux
VIP_HOST
Y
12 S_IN
I2S_OUT
Stereo
Audio Out
L
656/480P In
R
PCI BUS
DVD
HARD
DISK
HD-Theater block diagram
HD-Theater application example
Features:
• ATSC high-definition TV decoding
• 480P/ 720P/1080i output resolution from HDTV or DVD sources
• 5.1 Dolby DigitalTM, Pro-LogicTM and down-mixed 2.0 audio
• NTSC up-conversion and de-interlacing to 480P/ 720P/1080i
• Virtual surround spatialization for analog broadcast audio
• Record HD programs to disk
CX25871
VGA/RGB/YPrPb/NTSC
Output
I 2 S_OUT
ADC
CX23490
TS IN
PRI_OUT
VSB
Serial Data
CVBS
Ant2
2nd IF
Cable
TV
Tuner
Digital
Channel
Demod
SEC_OUT
Ant1
I2S_IN
Antenna
SDRAM
SDRAM
5.1
SP/DIF Out
features
TV
Tuner
C
MPEG
I2S_OUT
MPEG-2
Encoder
Serial Data
2nd IF
Ant2
Y Serial Bus
Host
Port
C
Composite or
S-Video In
specifications
656 Out
Ant1
Cable
CVBS
Antenna
and
Features:
Y
• Compresses broadcast video (ITU-R 656)
L
Stereo
Audio Out
Digital VCR application example
and broadcast audio (PCM) to MPEG PS/ES
R
• Allows real-time video preview in a window
• Simultaneous “watch and record” with VGA overlay
• Time-shift television programs
PCI BUS
HARD
DISK
Digital VCR block diagram
Product Features
Video Subsystem Features
• 10-bit video A/D
• Global video standards support
[NTSC (M, J, 4.43), PAL (B, D, G, H, I,
M, N, N-combination), SECAM (K, L)]
• Capture resolution up to 768 x 576
(square pixel PAL/SECAM)
• NTSC and PAL adaptive comb filter
for 2-D Y/C luminance and
chrominance separation
• AGC video circuit
• Multiple YCrCb and RGB pixel
formats and YUV planar formats
supported on output
• Selectable pixel density: 8, 16, 24
and 32-bits per pixel
• Performs complex clipping of video
source and VGA video overlay
• Permits different program control
and color space/scaling for even
and odd fields
• Supports Windows®
“Scatter/Gather” DMA
• High-quality multi-tap horizontal
and vertical image scaler for
decoded video or 4:2:2 sources
• ITU-R BT.656 8-bit or 10-bit 4:2:2
output port for MPEG-2 encoder
connection
• ITU-R BT.656/VIP 2.0 pixel input port
for MPEG-2 ML or HL decoder
connection
• Flexible VBI data capture for closed
captioning, teletext, other analog
broadcast data types
• Hue, brightness, contrast, saturation
control for video decoder
Audio Subsystem
• Low IF sampling direct from tuner
• CX23880: Global broadcast audio
support (BTSC-DBX, NICAM, A2,
EIAJ, FM)
• CX23881: European broadcast audio
support (NICAM, A2, FM)
• Decoded 48 KHz audio stream to PCI
bus for real-time encoding to MP3
• Integrated 90 dB SNR stereo audio
DACs to drive sound card or
headphones
• I2S Input port for external source
connectivity to on-board stereo DACs
• I2S Output port to drive
coaxial/optical digital audio interface
• Flexible audio sample rate converter
Fusion is a trademark of Conexant Systems, Inc.
www.conexant.com
© 2001, Conexant Systems, Inc. All Rights Reserved.
General Information:
Conexant and the Conexant logo are trademarks
of Conexant Systems, Inc. Other trademarks are
U.S. and Canada: (800) 854-8099
owned by their respective owners. Although Conexant
International: (949) 483-6996
strives for accuracy in all its publications, this material
Headquarters – Newport Beach
may contain errors or omissions and is subject to
change without notice.
THIS MATERIAL IS PROVIDED AS IS
4311 Jamboree Rd, P.O. Box C
AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
Newport Beach, CA 92660-3007
INCLUDING MERCHANTABILITY, FITNESS FOR A PARTICULAR
Order# 101550B
01-0844
PURPOSE AND NON-INFRINGEMENT.
Conexant shall not be
liable for any special, indirect, incidental or consequential
damages as a result of its use.
Multipurpose I/O Subsystem
Miscellaneous
• Bi-directional 33 Mbps VIP 2.0 host
port. Comapatible with the CX23490
all-format MPEG-2 decoder
(CX23880 only)
• Bi-directional 10 Mbps
Intel/Motorola-compatible general
purpose host port
• Unidirectional 10 Mbps parallel/serial
MPEG transport/data stream port.
Compatible with all Conexant digital
television channel demodulator ICs
• MPEG packet synchronization
• User-defined general purpose
input/output pins
• ACPI and power-down support
• Requires only one crystal for all
video and audio decoding
• 400 KHz serial bus master
• JTAG boundary scan interface
• Compact 176-pin TQFP
• Low power
PCI Subsystem
• 5 independent functions each with
target/master and local register
space (video, audio, MPEG port,
VIP 2.0 host port, GP host port)
• All RISC/control programs executed
on chip
• On-chip SRAM for PCI data buffering
up/down
• Vital product data
• DMA byte alignment
• PCI revision 2.2 compliant
Applications
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•
•
•
•
•
•
•
•
•
PC TV
PC TV
Digital television
Digital VCR
Analog and digital video editing
MP3 radio
PCI cable modem
PCI satellite modem
Data broadcast receiver
Media hub for home server