This section describes the overall
procedure to be followed while setting RBD. See Section 4.3, for the
detailed procedure with CAPI calls that can be used.
- Firstly, the configuration that was generated from Latte is run on the PCB, for
which optimal RBD needs to be found.
- Ensure that the CS state is achieved, this ensures that the start of EMB
boundary is locked onto for JESD204C and ILA boundary is locked onto for
JESD204B. Only after this, the *fcounter* registers would contain the intended
values. Ignore failures related to BUF state at this stage.
- Read back the
lane0/1/2/3_f_counter_all_lane_ready registers and calculate the
optimal RBD based on Section 2.2 for JESD204C and Section 3.2 for
JESD204B. In case there are multiple AFE ICs on the same board, ensure to read
the lane0/1/2/3_f_counter_all_lane_ready registers on all AFEs. The
highest out of all AFEs is then used for RBD calculation. If the values are
significantly different, different RBD values might have to be used for each
location of AFE on the PCB. See Section 4.3 for detailed procedure to
find and set the optimal RBD value.
- Optimal value found from previous
step is set and adcDacSync is executed. Ensure that the SYSREF is running
when adcDacSync is executed. The command adcDacSync resynchronizes
the JESD link. Running this command applies the RBD value that was set in Step
3.
This step is the second
iteration in identifying the right RBD
value.
link0/1_sysref_cnt_on_release_opportunity is read back. For 204C, (RBD_Step3+
link0/1_sysref_cnt_on_release_opportunity)%(64*E) is chosen as the
optimal RBD.
For 204B,
(RBD_Step3+ link0/1_sysref_cnt_on_release_opportunity)%(F*K/4) is
chosen as the optimal RBD.
RBD_Step3 is the RBD
calculated from Step 3.
- The configuration is then
modified with the optimal RBD as shown in Figure 4-1. In this
case the RBD has been set to a value of 0x80.
- The modified configuration sequence can now be frozen as the final configuration
with optimal RBD settings.
To summarize, initially the configuration is run once to identify the fcounter read
backs and calculate the optimal RBD. Once optimal RBD is found, it is updated in the
configuration sequence and used.