Video Surveillance/Security Applications
8-Channel Audio/Video Decoder with
Integrated PCIe Interface
Conexant’s portfolio includes a comprehensive suite of semiconductor
solutions for communications and consumer applications.
High Quality Audio and Video Decoders for Surveillance Applications
The CX25858 8-Channel Audio/Video Decoder with Integrated PCIe Interface
was designed for surveillance applications. The CX25858 contains eight high
quality NTSC/PAL video decoders with 10-bit A/Ds and 5-line comb filtering,
to generate the highest quality digital video output with the lowest possible
noise. This creates not only the best image quality for viewing, but enables
lower bitrates for compression devices using the output of the CX25858.
The video decoders within the CX25858 are optimized to lock to inputs with
low signal levels as well as line-locked cameras, both of which are common
in surveillance systems. Each video decoder may be scaled independently and
the CX25858 supports BT.656 as well as a variety of other interleaved digital
video output formats.
The CX25858 also contains eight high-quality mono audio A/Ds with I2S
PCIe Bridging
The CX25858 contains a PCIe 1.1 compliant x1 interface. It is ideal for
”capture card” applications in systems where eight channels of high-quality,
uncompressed video must be digitized and transmitted via PCIe for viewing,
compression, and/or analytics. The CX25858 can downscale digital video from
4:2:2 format to 4:1:1, reducing bandwidth requirements from 16 bits per pixel
to 12.
Additionally, the CX25858 supports the bridging of up to four channels of
digital video and audio from PCIe, and can output these streams over pins in
BT.656 or I2S-style interfaces, respectively.
Direct-Connection to Multi-Channel H.264 CODECs
The CX25858 supports byte, line, or frame-interleaved digital video outputs at
27, 54, or 108 MHz. Byte and line interleaved outputs are supported entirely
within the CX25858. Frame-interleaved outputs require that the CX25858
interface with external DDR2 memory. The CX25858 supports I2S and
multiplexed I2S audio outputs.
The CX25858 contains an interface for Maxim H.264 CODECs that permit the
CX25858 to bridge compressed data from Maxim devices to the PCIe bus.
This simplifies the Bill of Materials (BOM) and reduces costs in PCIe systems.
Distinguishing Features
• Eight High-Quality NTSC/PAL video decoders:
- Anti-alias filters
- 10-bit A/Ds
- 5-line comb filtering
- Independent scaling
• Eight Mono audio A/Ds
- Variable sample rates
- I2S outputs
• Flexible digital video output formats at 27, 54, and 108 MHz
- Byte-interleaved
- Line-interleaved
- Frame-interleaved (requires external DDR2 memory)
• PCIe 1.1 x1 interface
• Interface to Maxim CODECs for bridging of compressed data to PCIe
• Tiling and cascading functions (requires external DDR2 memory)
• Programmable Motion Detection
• 48 GPIO pins
Part Number CX25858
8-Channel Audio/Video Decoder with Integrated PCIe Interface Video
Video Surveillance/Security Applications
Additional Features
The CX25858 includes programmable motion detection logic,
There are two variants of the CX25858 offered — one with the
external DDR2 interface, and one without the interface. When
which can trigger flags or PCIe interrupts when motion is detected
equipped with DDR2, the CX25858 supports frame-interleaved
on incoming analog video streams.
video outputs, as well as a 2x2 CIF tiling mode, in which four CIF
images are tiled into a single D1 stream.
The CX25858 contains 48 GPIO pins, which maximize flexibility
The CX25858 may be cascaded with the CX25838 to create a
I2C interfaces and the Maxim interface are supported via GPIOs.
and allow customization to a variety of applications and designs.
16-channel system for sending video and audio data over PCIe.
DDR2 Memory
Analog Video Decoders
8x Composite NTSC/PAL
1 Input/Decoder
Independently Scaleable
8 CVBS Inputs
Motion Detection
DDR2 Interface
16-bit Data
Frame-Interleaving and Tiling
Digital Video I/O
4x BT.656 @
27, 54 and 108 MHz;
Byte, Line, or
DMA Controller
8 Downstream Video DMAs
4 Upstream Video DMAs
Audio DMAs
Data1[7:0], Clk1
Data2[7:0], Clk2
Data3[7:0], Clk3
Data4[7:0], Clk4
Mux-able I2S
Digital Audio I/O
I2S 16-bit @
8, 16, 32, 44.1, or 48 KHz;
Mux-able I2S
Mux-able I2S
Mux-able I2S
8 Mono
Audio Inputs
Broadband Audio A/Ds
8x Mono (4x Stereo)
PCI Express
x1 PCI Express
PHY Interface
3x I2C master
Maxim CODEC Host I/F
Data and Control
Motion and Board
Level Interrupts
PCI Express Bus
CX25858 Block Diagram
The CX25858-1x (contains DDR2 interface) is offered in a 23mm x 23mm, 288 pin fpBGA package.
The CX25858-2x (no DDR2 interface) is offered in a 14mm X 14mm, 233 pin fpBGA package.
Conexant Product Portfolio
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Doc# PBR-202315