Tx Pattern Generator - Xilinx 7 Series User Manual

15. Deassert TXDLYEN for the master lane.
16. Assert TXPHINIT for all slave lane(s). Hold this signal High until the rising edge of
17. Deassert TXPHINIT for the slave lane in which the TXPHINITDONE is asserted.
18. When TXPHINIT for all slave lane(s) are deasserted, assert TXPHALIGN for all slave lane(s).
19. Deassert TXPHALIGN for the slave lane in which the TXPHALIGNDONE is asserted.
20. When TXPHALIGN for all slave lane(s) are deasserted, assert TXDLYEN for the master lane.
21. Wait until TXPHALIGNDONE of the master lane reasserts. Phase and delay alignment for the

TX Pattern Generator

Functional Description
Pseudo-random bit sequences (PRBS) are commonly used to test the signal integrity of high-speed
links. These sequences appear random but have specific properties that can be used to measure the
quality of a link. The GTP transceiver pattern generator block can generate several
industry-standard PRBS patterns listed in
Table 3-18: Supported PRBS Patterns
In addition to PRBS patterns, the GTP transceiver supports 16-UI or 20-UI square wave test
patterns, depending on data width as well as a 2-UI square wave test pattern and PCI Express
compliance pattern generation (see
to check PLL random jitter often done with a spectrum analyzer.
7 Series FPGAs GTP Transceivers User Guide
UG482 (v1.9) December 19, 2016
TXPHINITDONE of the respective slave lane is observed.
Hold this signal High until the rising edge of TXPHALIGNDONE of the respective slave lane
is observed.
This causes TXPHALIGNDONE of the master lane to be deasserted.
multi-lane interface is complete. Continue to hold TXDLYEN for the master lane High to adjust
TXUSRCLK to compensate for temperature and voltage variations.
Name Polynomial
6 7
PRBS-7 1 + X + X
14 15
PRBS-15 1 + X + X
18 23
PRBS-23 1 + X + X
28 31
PRBS-31 1 + X + X
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Table 3-18.
Length of
Sequence
7
2 - 1 bits Used to test channels with 8B/10B.
ITU-T Recommendation O.150, Section 5.3.
PRBS-15 is often used for jitter measurement
15
2 - 1 bits
because it is the longest pattern the Agilent
DCA-J sampling scope can handle.
ITU-T Recommendation O.150, Section 5.6.
PRBS-23 is often used for non-8B/10B encoding
23
2 - 1 bits
schemes. It is one of the recommended test
patterns in the SONET specification.
ITU-T Recommendation O.150, Section 5.8.
PRBS-31 is often used for non-8B/10B encoding
31
2 - 1 bits
schemes. It is a recommended PRBS test pattern
for 10 Gigabit Ethernet. See IEEE 802.3ae-2002.
Table 3-19 and Figure 3-16). Clocking patterns are usually used
TX Pattern Generator
Description
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