4
SMS 8301A-K Key to Serial Component Digital Converter
Signal Processing
The input video key is passed through Analog Processing and
Filtering circuitry then applied to the Analog–to–Digital
Converter and Digital Filter block.
An A/D converter samples the video at 27MHz and converts it to
10–bit data.
The Key Delay delays the signal to make the time delay
introduced by the SMS 8301A-K match the delay of the SMS
8301A module.
The Calibration Display Generator uses the delayed Key/Y
channel to produce a signal which can be observed on an
oscilloscope connected at the module front panel. The resulting
display shows the key signal peak white and black levels and
calibration markers for each.
The Blanking Gate, Limiter and Rounder receives delayed Key/Y
data and a chroma channel data input corresponding to zero
color. It rounds 10-bit input data to 8 bits if required and adds
digital blanking level data as required.
The CCIR601 Encoder receives the Y and Chroma outputs of the
Blanking Gate, Limiter and Rounder and creates a SMPTE 125M/
CCIR601 format, parallel data output.
The Scrambler and Serializer receives the multiplexed CCIR601
(SMPTE 125M) data stream from the CCIR601 Encoder and
produces serial outputs conforming to the proposed SMPTE
259M/ EBU Tech 3267 standard.