SJA1105 UDP lose packet

zhengjianfei1 · ‎07-31-2023

Hello Nxp，

we are using Sja1105 to forward Lidar data in ADAS system. Lidar data contains UDP and RTR, UDP data slot is 600 microseconds, RTR data data slot is 1 second. When UDP data is close to RTR data, UDP data will be lost. When data is not through sja1105,we can see UDP and RTR are receive almost at the same time.

Could you give me some Suggestions about this problem?Thanks!

abdullahzafar · ‎08-03-2023

Hi zhengjianfei1,

I had a look at the configuration and dont see any problem with the configuration.

Could you please try to read out the error counters on the switch. This will help

is narrow down the problem. In our tool there should be a python script "read_highlevel_diagnostic_registers.py".

Try using it for reading out the counters. What is your hardware setup? are you using SJA 1105Q EVB, or you have

your own hardware?

BR,

Abdullah

zhengjianfei1 · ‎08-03-2023

Hi Abdullah，

Thanks for your suggestion！we read out all the registers of SJA1105 as attachment.

0x6x3 registers have value, means QUEUE FULL. But when 0x6x3 value becomes stable, 0x6x3 value will not increase when packet lose again. It seems like packet lose is not caused by QUEUE FULL.

we use our own hardware, and there will no frame lose if Interframe gap is not so short.

abdullahzafar · ‎08-09-2023

Hi zhengjianfei1,

I had a look at the error log, only QUEUE FULL is getting incremented. That should not have an impact on anything. No drop counter getting incremented indicates that the packets are not getting dropped by the switch. What happens if you make a direct connection without using the switch? In general, you will have to debug step by step to see where the packets are actually getting dropped.

BR,

Abdullah

abdullahzafar · ‎08-01-2023

Hi zhengjianfei1,

The issue is little unclear for me. Could you please tell me on how you configured the switch?

Which exact SJA1105 version are you using, is it SJA1105 Q or SJA1105 P? could you maybe

give more explanation on the issue? maybe use a diagram.

BR,

Abdullah

zhengjianfei1 · ‎08-02-2023

Hi Abdullah，

Thanks for your reply!

We use SJA1105Q, attach is our config file.

Our ethernet Architecture is as picture bellow:

Lidar send UDP frame to PC per 600 microsecond,and RTP frame per 1 second. When UDP frame and RTP frame have a short interval of time, the UDP frame will be lost.