Part Number: SN65DPHY440SS
Tool/software:
Hello, Amazon is using sn65dphy440s in a headset application and are seeing some issues.
Their software team reported a display hanging issue during a low content image streaming use case . Our triaging so far shows that this issue is related to higher than expected voltage (> 450mV) observed on the DSI interface at Retimer input during the HS Idle mode. Logs also show that display data streaming is interrupted. The issue is observed during a prolonged display streaming for few hours.
Our leading hypothesis is that retimer is not presenting the right terminations required for HS mode leading to out of spec voltage level at its input. Here are some captures where we observe the idle voltage on DSI_N signal is above 500mV.
We would appreciate your insights here to RC the issue and how to mitigate it. Is there any specific SW registers that we can access to read the status? Also let us know if you need any specific captures.
Retimer input showing DSI_DATA_N higher than 500mV during HS idle.
Zoomed during failure
Retimer output showing no activity
They are using only one lane DA0 for data. And yes we are seeing this issue across multiple units.
We did verify that the timing of THS-EXIT is more than 100ns ( ~900ns).Here is a capture taken with infinite persistence mode. We can clearly see that when fault happens, the DSI HS Idle level voltage levels exceed 400mV.
Please help with this issue.
