Introduction to PRBS Test
2
SLAA750 – July 2017
Copyright © 2017, Texas Instruments Incorporated
DAC38RF8x Test Modes
17
Example Short Test Pattern File
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18
DAC38RF8x EVM GUI
Low Level View
Tab Short Test Enable Register
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19
DAC38RF8x EVM GUI
Low Level View
Tab Short Test Alarm Register
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1
Introduction to PRBS Test
A pseudorandom binary sequence (PRBS) is a stream of binary information often used in testing high-
speed data-transmission signal integrity. Pseudorandom binary sequences are composed of an equal
distribution of 0s and 1s and only repeat themselves after 2
k – 1
cycles, where k is the order of the PRBS
test. The PRBS test replicates the worst-case data scenarios where the current received bit is unrelated to
previous bits. For more information on pseudorandom binary sequences, refer to the Advantest document,
DSP-Based Testing - Fundamentals 50, PRBS (Pseudo Random Binary Sequence)
(Okawara 2013).
The DAC38RF8x supports three different PRBS testing options: PRBS7, PRBS23, and PRBS 31. In this
test mode, the PRBS pattern is supplied to the DAC input, typically through an FPGA, and the pattern is
compared with the internally generated pattern of the DAC. If the received pattern matches the generated
pattern, the test will pass and confirm good signal integrity at the DAC input. Otherwise a flag in one of the
DAC registers is set to notify the user of a possible issue.
The following sections outline the required steps to implement the PRBS test using the DAC38RF8x EVM
by using the TSW14J56 capture card and corresponding TI GUI software. To run the test without using
the TI EVMs and GUIs, configure the DAC to the desired operating state and perform the register writes
provided in
to enable the PRBS test mode.
1.1
Required Hardware
This test procedure requires the following lab equipment:
•
DAC38RF8xEVM RevE board
•
TSW14J56 RevD board
•
5-V DC power supplies
•
Signal generator
•
Oscilloscope
1.2
Required Software
This test procedure requires the following software:
•
HSDC Pro Version 4.8 or higher
•
DAC38RF8x EVM GUI
