Appendix E HDTV Output Mode
CX25870/871
E.2 Allowable Interfaces for HDTV Output Mode
Flicker-Free Video Encoder with Ultrascale Technology
E.2 Allowable Interfaces for HDTV Output Mode
The interface that the CX25870/871 must use in HD Output Mode is either type
of video timing slave interface. In this configuration, the HSYNC* and VSYNC*
signals must be received as inputs while the BLANK* signal’s usage is optional.
The encoder cannot transmit the timing signals that initiate the start of a line or
the start of a frame in this mode at all. The CX25870/871 can provide a reference
clock output—CLKO, or not transmit it, as needed. The EN_OUT bit will control
whether or not a CLKO signal is active.
The BLANK* signal will not be required for the HDTV Output Mode
interface if the graphics controller outputs the digital codes for the analog
blanking level. For analog RGB component video outputs, the digital code for
blanking is 00 hex for digital R, G, and B. For offset analog RGB component
video outputs, the digital code for blanking is 10 hex for the digital R, G, and B
pixel inputs. Finally, for analog Component YPBPR video outputs, the digital code
for blanking is 10 hex for digital Y and 80 hex for digital Pr and Pb.
If the graphics controller does not possess the ability to output specific digital
codes, then a BLANK* signal is a necessary part of this interface.
E-2
Conexant
100381B
CONEXANT [ CONEXANT SYSTEMS, INC ]
