Brooktree
®

Brooktree Division • Rockwell Semiconductor Systems, Inc. • 9868 Scranton Road • San Diego, CA 92121-3707
619-452-7580 • 1-800-2-BT-APPS • FAX: 619-452-1249 • Internet: apps@brooktree.com • L848A_A

Distinguishing Features

• Fully PCI Rev. 2.1 compliant
• Auxiliary GPIO data port and video data
port
• Supports image resolutions up to
768x576 (full PAL resolution)
• Supports complex clipping of video
source
• Zero wait state PCI burst writes
• Field/frame masking support to throttle
bandwidth to target
• Multiple YCrCb and RGB pixel
formats supported on output
• Supports NTSC/SECAM/PAL analog
input
• Image size scalable down to icon using
vertical & horizontal interpolation
filtering
• Multiple composite and S-video inputs
• Supports different destinations for even
and odd fields
• Supports different color space/scaling
factors for even and odd fields
• Support for mapping of video to 225
color palette
• VBI data capture for closed captioning,
teletext and intercast data decoding

Additional Features
in Bt848A/849A Only

• Supports peaking
• Requires only one crystal
• Digital camera support through GPIO
port
• Support for WST decode (Bt849A only)

Applications

• PC TV
• Intercast receiver
• Desktop video phone
• Motion video capture
• Still frame capture
• Teletext/Intertext
• VBI data services capture

Bt848 is a complete, low cost single-chip solution for analog
NTSC/PAL/SECAM video capture on the PCI bus. As a bus master, Bt848 does
not require any local memory buffers to store video pixel data which signifi-
cantly minimizes the hardware cost for this architecture. Bt848 takes advantage
of the PCI-based system’s high bandwidth and inherent multimedia capability. It
is designed to be interoperable with any other PCI multimedia device at the
component or board level, thus enabling video capture and overlay capability to
be added to PCI systems in a modular fashion at low cost. The Bt848 solution is
independent of the PCI system bus topology and may be used in a variety of sys-
tem bus organizations: directly on a motherboard planar bus, on a card for a pla-
nar or secondary bus.
The Bt848A/849A are fully backward compatible enhancements to the
Bt848. The Bt848A and 849A both include all the functionality of the Bt848,
while adding support for peaking, single crystal operation, and digital camera
support.

Functional Block Diagram
Advance Information

This document contains information on a product under development.
The parametric information contains target parameters that are subject to change.

Analog
Mux
AGC
40 MHz
ADC
40 MHz
ADC
Decimation LPF
Ultralock™
and
Clock Generation
Video Timing
Unit
IIC JTAG
Pixel Format
Conversion
630 Byte FIFO
Digital Camera
Target
Initiator
PCI I/F
MUXIN
MUXOUT
SYNCDET
REFOUT
YIN
CIN
XTAL
Luma-Chroma
Separation
and
Chroma Demod

Single-Chip Video Capture for PCI

Bt848/848A/849A

Input (Bt848A/849A)
Horizontal, Vertical
and Temporal
Scaling
DMA Controller
and GPIO Port