Bt860/861
1.0 Functional Description
1.2 Functional Overview
Multiport YCrCb to NTSC/PAL /SECAM
1.2 Functional Overview
The Bt860/861 is a highly programmable 3.3 V multiport digital video encoder
with pixel synchronization and per-pixel blending capabilities. It is equipped with
three 8-bit YCrCb data ports that allow a variety of video and graphic overlay
configurations useful in video set top box applications.
The three 8-bit YCrCb data ports allow two video streams and one
alpha-blended overlay stream. For switching between video sources (such as a
video decoder and an MPEG source), while providing a common OSD interface
using the part’s overlay and alpha capabilities.
The Bt860/861's VID port uses a PLL and FIFO to allow direct interfacing
with asynchronous video sources, such as the Bt835 video decoder.
In slave mode, the Bt860/861 can be configured to accept either
ITU-R BT.656-compliant timing (EAV and SAV codes) or ITU-R BT.601 data
timing (HSYNC* and VSYNC* signals). The Bt860/861 can also act as timing
master, producing ITU-R BT.601 timing.
The Bt860/861 supports worldwide video standards, including:
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NTSC-M (N. America, Taiwan, Japan)
PAL-B, D, G, H, I (Europe, Asia)
PAL-M (Brazil)
PAL-N (Uruguay, Paraguay)
PAL-Nc (Argentina)
PAL-60, NTSC-443
SECAM
The Bt860/861 has six 10-bit current-out video DACs, specifically designed
for video systems requiring the generation of high quality composite, Y/C
(S-Video), and simultaneous component YUV or RGB (SCART) video signals.
Two of the composite output signals can be programmed with a 0–7 clock
luminance delay. The connection status of each DAC can be dynamically
monitored through the serial programming interface.
The Bt860/861 has several low power options, including sleep mode (only the
serial programming interface and PLL are operational), individual DAC disable,
PLL disable, and 3.3 V operation. The 3.3 V digital inputs can be configured to
be 5 V-tolerant.
The luminance upsampling filter is enhanced to provide a narrow transition
region and a low stopband. Programmable luminance sharpness filters provide
0,1, 2, and 3.5 dB peaking options at higher video frequencies, and four reduction
filters are added for smoothed step response. To reduce the complexity of the
required reconstruction filter, 2x upsampling is implemented.
The Bt860/861 can produce internally generated colorbars and blue field
signals.
A 400 kHz serial programming interface (I2C-compatible) is provided for fast
system programming.
The Bt860/861 provides support for Closed Captioning (CC) and Extended
Data Services (XDS), Teletext (WST system B), Copy Generation Management
System (CGMS), VARIS-II, and Wide Screen Signaling (WSS).
The Bt860 and Bt861 are functionally identical except that the Bt861 can
output the Macrovision 7.x anticopy algorithm.
D860DSA
Conexant
1-5
CONEXANT [ CONEXANT SYSTEMS, INC ]
