Other Parts Discussed in Thread: ALP
Hi,
I’m writing you because we've found an issue on FPD link III, we're using:
- DS90UB949TRGCTQ1 serializer
- DS90UB948TNKDRQ1 deserializer
- The link is configured to work on dual-lane
- Cable Dacar 535, HSD to HSD from Rosemberger, with characteristic impedance of 100Ohms
- All the errata for Ser and Deser are been applied
Using a wiring of 36cm, a transient occurs in which the video sent to the screen flickers and sometimes even disappears, and then stabilizes and no longer manifests the phenomenon. Using cables of longer length we never find the problem.
A first observation of the analysis we've found a correlation between the flickers screen and lock -> unlock transition.
Analysis 1:
Using ALP SW we’ve run Margin Analysis Tool.
Results:
Analysis 2:
Link_Error_Count Register (Address 0x41) Deser Side has been set with 0x1F, it means maximum threshold.
Results: Flickers screen.
Analysis 3:
Link_Error_Count Register (Address 0x41) Deser Side has been set with 0x1F.
AEQ_TEST Register (Address 0x35) has been set initial with 0x40 and then 0x00
Results: Flickers screen.
Analysis 4:
Link_Error_Count Register (Address 0x41) Deser Side has been set with 0x1F.
Adaptive_EQ_Bypass Register (Address 0x44) has been set initial with 0x81, it means EQ2 = 0x0 and EQ1 = 0x4
Results: Flickers screen.
We would like to have your support to understand the causes, how to carry on the analysis to get the solution.
Thank you in advantage for your availability and support.
Angelo
