SNLA433 august   2023 DS320PR1601 , DS320PR410 , DS320PR810 , SN75LVPE5412 , SN75LVPE5421

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Device Overview
    1. 2.1 Receiver Equalization
    2. 2.2 Redriver Linearity
    3. 2.3 PCIe Links with Linear Redrivers
    4. 2.4 Redriver EQ Tuning
      1. 2.4.1 Detailed Description of Parameters Calibration
  6. 3General Guidelines for Optimal CTLE and Gain Selection
  7. 4Summary
  8. 5References

Detailed Description of Parameters Calibration

  1. Amplitude or VOD Calibration: Amplitude calibration is done at TP3 using a mixed clock and low frequency pattern at 32Gbps. Under this condition, compliance must be confirmed with PCIe Gen5 using P1 through P9 presets.
  2. RJ Calibration is performed at TP3. PCIE calibration pattern is used at P4 along with the SigTest Phoenix 5.1.04 RJ_SJ_CAL template to analyze RJ. Target RJ is 0.5ps rms at TP3.
  3. SJ Calibration is similar to RJ and the target value is 1-5ps.
  4. Insertion Loss Calibration is performed at TP2. Figure 2-7 and Figure 2-8 show loss targets for different elements within the signal path and CBB/CLB with ISI loss board setup.
  5. AIC DMI (Differential Mode Interference) is performed at TP2 with 31.8 dB total channel loss at TP2. Phoenix uses 4.2 dB for AIC package loss. P4 preset and DMI/CMI patterns modulated with 2.1 GHz signal are used to achieve targeted 5-30 mV DMI at TP2.
  6. CMI is the same as DMI and performed at TP2 is as well. A 120 MHz CMI is used to achieve a target value of 150 mV.
  7. TX EQ Calibration: BERT is calibrated to the noise values. Using presets P5/6/8/9, the best CTLE and preset are selected based on which produce the best eye area at TP2.
  8. Insertion loss decremented—from 36 dB—in 0.5 d B/step, DMI in 3 mV increments, SJ in 10 mUI increments, SJ in 10 mV increments, and device CTLE gain swept from 7 through 12 to achieve best Eye Height (EH) and Eye Width (EW).

The DS320PR1601 performance matrix in Table 2-3 shows the device performance with various pre-channel and post-channel combinations using the RX Equalization methodology just discussed.

GUID-20230803-SS0I-QFJJ-1BGF-GDFNHZPWBZDJ-low.png Figure 2-11 AIC Testing Overview

After calibration and operating in AIC mode, Table 2-3 shows the device performance with various pre-channel and post-channel combinations using PCIe Gen5 RX Equalization methodology

Table 2-3 Device Performance Across Pre-Channel and Post-Channel Losses
Pre-Channel Loss (dB) Post-Channel Loss (dB) EQ Index/DC Gain/Preset Eye Width (UI) Eye Height (mV)
10 32 2/L2/P6 0.39 35.74
14 26 2/L2/P6 0.41 46
14 32 7/L2/P6 0.35 36.83
18 22 2/L4/P6 0.4 72.5
18 26 3/L2/P6 0.4 48.21
22 18 1/L2/P6 0.44 67.7
22 22 3/L2/P6 0.39 40.91
22 26 7/L2/P6 0.43 48
26 18 3/L2/P5 0.37 33.1
26 22 4/L2/P6 0.4 39.7
26 26 4/L2/P6 0.36 28.4
29 18 4/L2/P6 0.35 39.7
29 22 4/L2/P6 0.34 29.59