I am testing an FPGA interface to the DDR output from an AD9467 ADC. One of the test modes for the AD9467 is to generate a PN 9 sequence. The first three numbers I read from the ADC are similar to three listed in the data sheet, i.e. 0x87BE, 0xAE64, 0x929D, with the exception of the MSB.
I am using two's complement data format. I have a couple of questions :
1) Does the data format used affect the output from the PN 9 sequence?
2) Is it possible to post the whole sequence to the forum, I'm assuming there are only 511/16 ~= 32 x 16 bit words? It would be useful to have the expected sequence for each data format, i.e. offset binary, twos complement and Gray coding.
3) Is example (say) C code available for generating the sequence used in the AD9467 including the initial seed? I have implemented the x9 + x5 + x0 polynomial and it seems to give different results.
Thanks in advance,