Grass Valley 2090MDC - Manual (Page 27)

2090MDC Instruction Manual 21
Functional Description
UV and Y FIFOs
The UV and Y FIFOs act as buffers between the output of the scaler and the
monitor output section. The FIFOs perform field rate conversion from
60 Hz to 59.94 Hz.
Colorimetry Converter
The colorimetry converter converts the color value from the coding matrix
used for HD video (ITU BT 709) to the corresponding value (ITU BT 601) in
the standard definition coding matrix. This conversion is done in the SD
FPGA.
Multiplexer
The multiplexer section of the SD FPGA multiplexes the Y and UV data into
one D1 data string.
NTSC/RGB Encoder
The D1 signal from the Multiplexer splits off and one path enters the NTSC
Encoder and RGB Converter circuitry. The digital parallel data in D1
format is encoded into analog NTSC and also converted to analog RGB.
These signals are fed through output drivers to the two looping BNCs for
NTSC/PAL video and a set of RGB outputs for feeding component moni-
tors.
Scrambler and Serializer
The other D1 signal path from the Multiplexer enters Scrambler and Serial-
izer circuitry which converts the output into two SDI outputs. These SDI
outputs are sent to an SD driver and then to the rear connector assembly as
the two 601 outputs.
Timing
Each FPGA contains timing circuitry to generate all necessary input and SD
video timing signals needed by the other components. An output pixel
clock is also produced via a phase lock loop locked to the input bit rate.