SBAA525A september   2021  – may 2023 AFE7900 , AFE7920 , AFE7950

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Highlighted Products
    2. 1.2 Device Loopback Modes
      1. 1.2.1 ADC to DAC JESD Loopback
      2. 1.2.2 ADC to DAC Low Latency Loopback
  5. 2Tests and Results
    1. 2.1 Test Methodology
      1. 2.1.1 Hardware Setup
        1. 2.1.1.1 ADC to DAC JESD Loopback
        2. 2.1.1.2 ADC to DAC Low Latency Loopback
      2. 2.1.2 GUI Setup
        1. 2.1.2.1 ADC to DAC JESD Loopback
        2. 2.1.2.2 ADC to DAC Low Latency Loopback
      3. 2.1.3 Test Conditions
      4. 2.1.4 Test Results
        1. 2.1.4.1 ADC to DAC JESD Loopback
          1. 2.1.4.1.1 JESD 122.88 MSPS
          2. 2.1.4.1.2 JESD 184.32 MSPS
          3. 2.1.4.1.3 JESD 245.76 MSPS
          4. 2.1.4.1.4 JESD 368.64 MSPS
          5. 2.1.4.1.5 JESD 491.52 MSPS
        2. 2.1.4.2 ADC to DAC Low Latency Loopback
  6. 3Conclusion
  7. 4References
  8. 5Revision History

2.1.2.1 ADC to DAC JESD Loopback

AFE supports RX ADC to DAC loopback through the internal JESD block. This can be enabled by setting jesdLoopBackEn to True. Below are the conditions to be satisfied for using this feature.

  1. The ADC and DAC interface rates must be same.
  2. The JESD settings and the lane rates must be same for both RX and TX.
  3. RXA must loop back to TXA, RXB must loop back to TXB, and so on.
  4. Loopback mode is enabled using the check box as shown in Figure 2-3.
    GUID-20210810-SS0I-BTHM-DLNG-FVLGBZMHWWHV-low.png Figure 2-3 ADC to DAC JESD Loop Back Enable Mode