MIMXRT685-EVK_How to create function of hand off to secondary master under I3C interface?

[Jin_Tien]

Hi,

As the title, I wish to find the SDK sample and try to verify the mulit-master function, could you provide the SDK sample for this application?

Or could I physically new add second master device on the I3C bus, then physically remove the original master, then re-do the bus initial via new add master device. Will this action can let my new add master device become new master and read/write data normally?

Have a nice day,

Jin Tien

[diego_charles]

Hi @Jin_Tien 

I hope you are doing well! 

I can not tell if the alternative process that you describe will be reliable.

According to the RT685 UM11147  section  26.7.2.7 Handing off mastership to another slave and getting it back the master could request to an slave to become a master or wait for the handoff request for an slave.

Currently, I have not found an SDK example to handle handoff. 

Diego

[Jin_Tien]

Hi Charles,

After checking many cases in NXP community, I found the ccc_command example code which can help me in this issue.

The testing process as below:

1. Primary master init the I3C bus.

2. Remove the primary master physically, then connect the secondary master (RT685) on the I3C bus.

3. Init and config the RT685, then send CCC_DISEC, CCC_RSTDAA, CCC_SETDASA sequentially. (To reset the DA set by primary master, then set the new DA by RT685)

4. Ping the slave with R/W command.

Result: Did observe the ACK waveform while ping the slave with new DA.

According to above testing, this issue can be closed.

However, I've another issue about how to access the large bytes register address, could you help to check this issue? Thanks!

Link as below: 

https://community.nxp.com/t5/i-MX-RT/MIMXRT685-EVK-How-to-access-I3C-device-register-with-8-bytes/m-...