SBAA637 June   2024 AFE7950

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
  5. 2 SPI Failure During Bring-Up
    1. 2.1 Detail Regarding Chip Readouts
    2. 2.2 Failure and Fix for Chip Read Check
    3. 2.3 Poll Check for SPI Access for PLL Page
    4. 2.4 Failure and Fix for the SPI Poll Check for PLL Page Access
    5. 2.5 Read Check Indicating Status of Fuse Farm Autoload
    6. 2.6 Failure and Fix for Autoload Read Check
  6. 3 Macro Failure Breaking the Bring-Up Flow
    1. 3.1 Read Check for Macro Error and Poll Check for Macro Done
    2. 3.2 Failure and Fix for Macro Error and Poll check for Macro Done
  7. 4 AFE PLL Failure
    1. 4.1 Read Check for PLL Lock
    2. 4.2 Failure and Fix for Read Check of PLL
  8. 5 AFE Internal Sysref Flag Failure
    1. 5.1 Read Check Status of Sysref Flag Bit
    2. 5.2 Failure and Fix for Read Check Status of Sysref Flag Bit
  9. 6 JESD Link Check Failure
    1. 6.1 Multiple Read Checks Indicating Status of JESD Linkup
    2. 6.2 Failure and Fix for JESD Error
  10. 7 Validating Serdes and JESD Link using CAPI
    1. 7.1 Useful Serdes Debug CAPIs
    2. 7.2 Useful JESD Debug CAPIs
  11. 8 TX Chain Validation
  12. 9 RX Chain Validation
  13. 10Device Health
  14. 11Summary
  15. 12References

8 TX Chain Validation

  1. We have CAPI dacJesdConstantTestPatternValue which can send fix I and Q value in TX Chain at the input to NCO. A Single tone at NCO value and the tone amplitude can be controlled using the I and Q values.
  2. This test is useful in case of checking if TX Chain is configured properly when random or improper data in TX spectrum, In case of improper data if we enable the dacJesdConstantTestPatternValue and see tone output is correct at NCO, we can narrow down the problem is not in TX chain but in JESD block of TX chain or the Serdes linkup or JESD of FPGA/ASIC.
  3. We can use this test single tone for TX output power check or calibrating RX chain equivalent to a signal generator and also program the frequency by configuring the TX NCO dynamically with in some range, To configure NCO dynamically, we can use CAPI updateTxNco.
  4. Also, in case of any spur debug. we can easily figure out the coupling point is inside AFE or external by changing the TX DSA using CAPI setTxDsa. If the spur level change with DSA in can be coupling somewhere internally in Chain if spur level does not change with TX DSA or scale non-linearly it can be external coupling or two sources with external coupling dominating.
  5. AFE CAPI Libs also has option to internally read the dbfs power with in Tx Chain, using CAPI readTxPower. This can also be handy during debug test.