Valkyrie Knowledge Base

PRBS Config & Status

Ports on some high speed modules support layer 1 PRBS testing. For these ports, an additional PRBS Config & Status sub-tab will appear in the main Resource Properties tab as shown in the image below.

All ports supporting layer 1 PRBS testing will support the Polynomial PRBS31. If more are supported they can be selected from the drop down menu you get when you click on the selection box. Some ports supporting layer 1 PRBS testing will support Invert Pattern. Check the box to invert the test pattern if supported by the port. With Statistics mode Accumulative PRBS Status Counters are accumulated since last time Clear PRBS Counters was pressed. With Last Second PRBS Status Counters are shown for the last second. Lane/Link is for future use.

PRBS Testing 

The physical lanes of ports supporting layer 1 PRBS testing can be set to PRBS mode, where they transmit a pseudo-random binary sequence (PRBS) bit pattern, which can be useful for testing physical cabling and connectors.

On the transmit side, you select whether each lane should be in PRBS mode, and also whether it should be subject to error injection:

Errors can be injected individually by clicking a button, or continuously by specifying a rate. Error injection also works for lanes that are not in PRBS mode, and can thus be used to simulate bit-level errors into the CAUI level.

On the receive side, you can see whether each physical lane has locked onto the PRBS pattern, and the number of bit errors while in PRBS lock: