Visible to Intel only — GUID: ohy1513384526098
Ixiasoft
Visible to Intel only — GUID: ohy1513384526098
Ixiasoft
3.1.1.4. Data Pattern Generation
The E-tile has an on-chip pseudo random pattern generation block that operates in all bit modes and can generate several patterns. In addition to this, it can generate an 80-bit user-defined pattern.
There are patterns supporting both NRZ and PAM4. Pseudo random bit sequence (PRBS) NRZ patterns are different from PAM4 patterns. Different specifications such as CEI OIF and IEEE 803.2, refer to quaternary PAM4 patterns differently. QPRBS13 is identical to PRBSQ13 and QPRBS31 is identical to PRBSQ31.
As defined in OIF Clause 16: CEI-56G-VSR-PAM4 Very Short Reach Interface specifications, typically, each cycle of PRBSQ13 is 8191 unique symbols long. Each cycle is formed by gray coding and PAM4 encoding of bits from two repetitions of the PRBS13 pattern and used for transmitter compliance testing.
For more details on PRBS13Q pattern generation, refer to CEI-56G-VSR-PAM4 specifications. On similar lines, the PRBS31Q pattern is a repeating 231 -1 symbols long, formed by gray coding and PAM4 encoding of the PRBS31 pattern. This pattern is used for receiver testing.
NRZ Mode | PAM4 Mode |
---|---|
PRBS7 | PRBS7Q |
PRBS9 | PRBS9Q |
PRBS11 | PRBS11Q |
PRBS13 | PRBS13Q |
PRBS15 | PRBS15Q |
PRBS23 | PRBS23Q |
PRBS31 | PRBS31Q |
User-defined 80-bit Pattern |
More details on these patterns are as follows:
2 7 –1 PRBS pattern This standard PRBS pattern 11 is based on the generator polynomial x7 + x6 + 1 (refer to ITU V.29)
2 9 –1 PRBS pattern This PRBS pattern is based on the generator polynomial x9 + x5 + 1 (refer to CCITT O.151/ITU-T O.151)
2 11 –1 PRBS pattern This PRBS pattern is based on the generator polynomial x11 + x9 + 1 (refer to CCITT O.151/ITU-T O.151)
2 13 –1 PRBS pattern This PRBS pattern is based on the generator polynomial x13 + x12 + x2 + x + 1 (refer to CCITT O.151/ITU-T O.151)
2 15 –1 PRBS pattern This PRBS pattern 12 is based on the generator polynomial x15 + x14 + 1 (refer to CCITT O.151/ITU-T O.151)
2 23 –1 PRBS pattern This PRBS pattern 13is based on the generator polynomial x23 + x18 + 1 (refer to CCITT O.151/ITU-T O.151)
2 31 –1 PRBS pattern This PRBS pattern 14is based on the generator polynomial x31 + x28 + 1
For more details on Register Read/Write support and programming, refer to PMA Register Map and PMA Attribute Codes to configure these parameters.