PN9 testing codes for AD9634

Question

Hello, everyone! 
 I am unable to find seed value for PN9 sequence. ITU-T standard says, that it should be 0x1ff; AN_877 says 0x092. But none of this equals the code that I get from ADC. 
 Maybe someone can post the seed value and 3-5 first output words? 
 Thanks in advance, 
 Alexander Orlov.

J.Harris · Accepted Answer

Hi Alexander, 
 I think I have the solution for you. The LFSR has the correct equation for the PN9 sequence, but it is actually a 15 bit LFSR with the 15th bit inverted. Your output for the 12 bits should be taken from the 14th down to the 3rd flop output (since the output of the converter is 12 bits). I think if you use these characteristics, you should obtain the right sequence at the output. Let me know if you have additional questions. 
 Regards, 
 Jon)

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PN9 testing codes for AD9634