The SMPTE ST 259 and SMPTE ST 292 specifications define a common channel coding for both SD-SDI and HD-SDI. This channel coding consists of a scrambling function (G1(X) = X9 + X4 + 1), followed by NRZI encoding (G2(X) = X + 1).
The scrambling submodule implements the channel coding by iteratively applying the scrambling and NRZI encoding algorithm to each bit of the output data, processing the LSB first. The code handles all transmit data: SD (10 bits wide), HD/3G (20 bits wide), 6G (40 bits wide), and 12G (80 bits wide).
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