SBAA543 July   2022 AFE7900 , AFE7920 , AFE7950

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2JESD204C
    1. 2.1 Basic Review of JESD204C Protocol
    2. 2.2 Finding Optimal RBD for JESD204C
  5. 3JESD204B
    1. 3.1 Basic Review of JESD204B Protocol
    2. 3.2 Finding Optimal RBD for JESD204B
  6. 4Setting RBD in AFE79xx
    1. 4.1 Register Map
    2. 4.2 Setting RBD in Configuration Sequence
    3. 4.3 Finding Optimal RBD using CAPI
      1. 4.3.1 Use Case with 1 JESD Links
      2. 4.3.2 Use Case with 2 JESD Links
      3. 4.3.3 Use Case with 3 JESD Links
      4. 4.3.4 Use Case with 4 JESD Links
  7. 5Fixing Potential Alarms Related to RBD
    1. 5.1 RBD Alarm
    2. 5.2 SoEMB Close to LEMC Edge
    3. 5.3 Start of ILA Close to LMFC Edge
  8. 6References

Use Case with 1 JESD Links

In this case, lanes in top JESD and bottom JESD are part of a single JESD link. In this case, based on lane0_f_counter_all_lane_ready in the first page, link0_rbd_m1 is set in the first page.

Example:

  1. Read Page 0x16[2] : lane0_f_counter_all_lane_ready = 16

    getAllLaneReady(afeInst,0,&laneAllReady)

    laneAllReady = 16

  2. Obtain valid range of RBD.

    getGoodRbdRange(afeInst,0,&rbdMin,&rbdMax)

    rbdMin = 17

    rbdMax = 35 (Based on skew = 3, rbdMax = min (allLaneReady) + BufferDepth -10 = 16 - 3 + 32 - 10).

  3. In this example, optimal value is chosen as rbdMin + 3 = 20. In cases with multiple AFEs on a PCB, valid ranges can be looked at for all AFEs and optimal RBD can be chosen.
  4. The optimal RBD is set and adcDacSync is run.

    setManualRbd(afeInst,0,20)

    adcDacSync(afeInst,1)

  5. Read back link0_sysref_cnt_on_release_opportunity from the first page.

    getSysrefCntOnReleaseOpp(afeInst,0,&readVal)

    If readVal=1, optimal RBD is chosen as (20+1)%64 = 21

  6. In the config, value of 21 is set for the link0_rbd_m1 in the first page. In Latte, sysParams.jesdRxRbd is set to [21,21,21,21]