Intel® Stratix® 10 GX Transceiver Signal Integrity Development Kit User Guide

ID 683206
Date 2/21/2023
Public
Document Table of Contents

6.3.7. The LPBK Tab

The LPBK tab allows you to perform on-board loopback tests.

Figure 24. The LPBK Tab

The following sections describe controls on the LPBK tab.

Status

Displays the following status information during a loopback test:
  • PLL Lock: Shows the PLL locked or unlocked state.
  • Pattern Sync: Shows the pattern synced or not synced state. The pattern is considered synced when the start of the data sequence is detected.
  • Details: Shows the PLL lock and pattern status:

Port

Allows you to specify which interface to test. The following port tests are available: LPBKx6

PMA Setting

Allows you to make changes to the PMA parameters that affect the active transceiver interface. The following settings are available for analysis:
  • Serial Loopback: Routes signals between the transmitter and the receiver.
  • VOD: Specifies the voltage output differential of the transmitter buffer.
  • Pre-emphasis tap:
    • 1st pre: Specifies the amount of pre-emphasis on the pre-tap of the transmitter buffer.
    • 2nd pre (L-Tile): Specifies the amount of pre-emphasis on the second pre-tap of the transmitter buffer.
    • 1st post: Specifies the amount of pre-emphasis on the first post tap of the transmitter buffer.
    • 2nd post (L-Tile): Specifies the amount of pre-emphasis on the second post-tap of the transmitter buffer.
  • Equalizer: Specifies the AC gain setting for the receiver equalizer in four stage mode.
  • DC gain: Specifies the DC gain setting for the receiver equalizer in four stage mode.
  • VGA: Specifies the VGA gain value.

Data Type

Specifies the type of data contained in the transactions. The following data types are available for analysis.
  • PRBS 7: Selects pseudo-random 7-bit sequences.
  • PRBS 15: Selects pseudo-random 15-bit sequences.
  • PRBS 23: Selects pseudo-random 23-bit sequences.
  • PRBS 31: Selects pseudo-random 31-bit sequences.
  • HF: Selects highest frequency divide-by-2 data pattern 10101010.
  • LF: Selects lowest frequency divide-by-33 data pattern.

Error Control

Displays data errors detected during analysis and allows you to insert errors:
  • Detected errors: Displays the number of data errors detected in the hardware.
  • Inserted errors: Displays the number of errors inserted into the transmit data stream.
  • Insert: Inserts a one-word error into the transmit data stream each time you click the button. Insert is enabled only during transaction performance analysis.
  • Clear: Resets the Detected errors and Inserted errors counters to zeroes.

Run Control

TX and RX performance bars: Show the percentage of maximum theoretical data rate that the requested transactions are able to achieve.

Start: This control initiates the loopback tests.

Data Rate (H-Tile): Displays the XCVR type and data rate of each channel.
Figure 25. LPBK Data Rate

Tx (Mbps) and Rx (Mbps): Show the number of bytes of data analyzed per second.