4-Channel Audio/Video Decoder with Integrated PCIe
Interface
CX25854
High Quality Audio and Video Decoders for Surveillance Applications
The CX25854 4-Channel Audio/Video Decoder with Integrated PCIe Interface was
designed for surveillance applications. The CX25854 contains four 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 CX25854.
The video decoders within the CX25854 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
CX25854 supports BT.656 as well as a variety of other interleaved digital video
output formats.
The CX25854 also contains four high-quality mono audio A/Ds with I
2
S outputs.
4
4
PCIe Bridging
The CX25854 contains a PCIe 1.1 compliant x1 interface. It is ideal for "capture
card" applications in systems where four channels of high-quality, uncompressed
video must be digitized and transmitted via PCIe for viewing, compression, and/or
analytics. The CX25854 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 CX25854 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
I
2
S-style interfaces, respectively.
Distinguishing Features
Four High-Quality NTSC/PAL video
decoders:
– Anti-alias filters
– 10-bit A/Ds
– 5-line comb filtering
– Independent scaling
Four Mono audio A/Ds
– Variable sample rates
–
I
2
S 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
–
–
–
Direct-Connection to Multi-Channel H.264 CODECs
The CX25854 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
CX25854. Frame-interleaved outputs require that the CX25854 interface with
external DDR2 memory. The CX25854 supports I
2
S and multiplexed I
2
S audio
outputs.
The CX25854 contains an interface for Maxim H.264 CODECs that permit the
CX25854 to bridge compressed data from Maxim devices to the PCIe bus. This
simplifies the Bill of Materials (BOM) and reduces costs in PCIe systems.
Part Number CX25854
Description
CX25854 4-Channel
Video/Audio Decoder with Integrated
PCIe Interface
CONEXANT [ CONEXANT SYSTEMS, INC ]
