Intel® Cyclone® 10 GX Transceiver PHY User Guide

ID 683054
Date 4/14/2023
Document Table of Contents PRBS Pattern Generator (Shared between Enhanced PCS and Standard PCS)

You can use Cyclone® 10 GX pseudo-random bit sequence PRBS generator to simulate traffic without developing or fully implementing any upper layer of a protocol stack. The PRBS generator in Cyclone® 10 GX devices is a shared hardened block between the Standard and Enhanced datapaths through the PCS instead of being two unique instances: one for Standard PCS and one for the Enhanced PCS. There is only one set of control signals and registers for using this feature. The data lines from the various PCSes and shared PRBS, are muxed before they are sent to the PMA. When the PRBS generator is enabled, the data on the PRBS data lines is selected to be sent to the PMA. At any instant, either the data from the PCS or the data generated from the PRBS generator, is sent to the PMA.

The PRBS generator can be configured for two widths of the PCS-PMA interface: 10 bits and 64 bits. PRBS9 is available in 10-bit and 64-bit PCS-PMA widths. All other PRBS patterns are available in 64-bit PCS-PMA width only. The PRBS generator patterns can only be used when PCS-PMA interface width is configured to 10 bits or 64 bits.

Table 179.  Supported PRBS Patterns
PRBS Pattern 10 bit PCS-PMA width 64 bit PCS-PMA width
PRBS7: x7 + x6 + 1  


PRBS9: x9 + x5 + 1



PRBS15: x15 + x14 + 1



PRBS23: x23 + x18 + 1



PRBS31: x31 + x28 + 1



PRBS test patterns may be considered equivalent to "noise". Use these patterns to test the transceiver link with a noisy signal by placing the transceiver in loopback mode.

Use PRBS7 and PRBS9 to test transceiver links with linear impairments, and with 8B/10B.

Use PRBS15 for jitter evaluation.

Use PRBS23 or PRBS31 for jitter evaluation (data-dependent jitter) of non-8B/10B links, such as SDH/SONET/OTN jitter testers. Most 40G, 100G, and 10G applications use PRBS31 for link evaluation.

Figure 183. PRBS Generator for Serial Implementation of PRBS9 Pattern


All supported PRBS generators are similar to the PRBS9 generator.

Refer to the Reconfiguration Interface and Dynamic Reconfiguration chapter for configuration details.