Generating PRBS Frames

When PRBS transmission should be visible through a PyRogue tree, PyRogue provides pyrogue.utilities.prbs.PrbsTx. It wraps the underlying rogue.utilities.Prbs generator and exposes transmit size, period, enable state, and counters as tree variables and commands.

The direct rogue.utilities.Prbs form is the smaller fit for scripts and standalone validation graphs that do not need a tree-managed control surface.

PRBS transmit paths commonly drive traffic into FPGA firmware/VHDL checkers during link bring-up and integration testing.

Common Controls

The transmit wrapper is usually configured around:

  • txSize Payload size for generated frames.

  • txPeriod Background transmit period in microseconds.

  • txEnable Start or stop continuous generation.

  • genPayload Enable or disable payload generation.

  • width and taps PRBS state width and feedback polynomial selection.

  • sendCount Include a transmitted count field when the test setup expects it.

The direct Rogue endpoint has the matching lower-level controls such as genFrame(size), enable(size), disable(), setTxPeriod(period), setWidth(width), and setTaps(taps).

Using PrbsTx In A Tree

It is the right choice when operators or client code should be able to inspect or control transmit settings such as enable state, frame size, frame period, and generator counters through the PyRogue tree.

Python Direct-Utility Example

import rogue.utilities as ru
import rogue.utilities.fileio as ruf

# Capture generated test traffic to file.
fwrite = ruf.StreamWriter()
fwrite.setBufferSize(1000)
fwrite.setMaxSize(1_000_000)

# Create PRBS source endpoint.
prbs = ru.Prbs()

# Route generated frames into writer channel 0.
prbs >> fwrite.getChannel(0)

# Capture 1000 test frames of 1000 bytes each.
fwrite.open("test.dat")
for _ in range(1000):
   prbs.genFrame(1000)
fwrite.close()

Python Tree-Managed Example

import pyrogue.utilities.fileio as puf
import pyrogue.utilities.prbs as pup

# Add tree-managed file writer and PRBS transmitter.
fwrite = puf.StreamWriter()
root.add(fwrite)

prbs = pup.PrbsTx()
root.add(prbs)

# Transmit PRBS stream into writer channel 0.
prbs >> fwrite.getChannel(0)

C++ PRBS Generator Example

#include <rogue/utilities/Prbs.h>
#include <rogue/utilities/fileio/StreamWriter.h>
#include <rogue/utilities/fileio/StreamWriterChannel.h>

namespace ru  = rogue::utilities;
namespace ruf = rogue::utilities::fileio;

// Capture generated test traffic to file.
auto fwrite = ruf::StreamWriter::create();
fwrite->setBufferSize(10000);
fwrite->setMaxSize(100000000);
fwrite->setDropErrors(true);

// Create PRBS source endpoint.
auto prbs = ru::Prbs::create();

// Route PRBS output to writer channel 0.
prbs >> fwrite->getChannel(0);

// Capture 1000 test frames of 1000 bytes each.
fwrite->open("test.dat");
for (int i = 0; i < 1000; ++i) prbs->genFrame(1000);
fwrite->close();

API Reference