I3C Master IBI Pending Read Notification via Repeated START

[bell_huang]

I am using two NUCLEO-U385RG-Q boards for I3C communication — one configured as the Controller (Master) and the other as the Target (Slave). I am trying to implement an IBI event with Pending Read Notification, and would like to know whether it is possible to perform Repeated START between the IBI and the subsequent Private Read?

The transfer format for Pending Read Notification can be referenced in the following document, specifically Figure 6 – MCTP over I3C packet transfer format: I3C Target to I3C Controller:

Management Component Transport Protocol (MCTP) I3C Transport Binding Specification 

From the transfer format, it can be seen that Pending Read Notification essentially means that after the Controller receives an IBI event, it then performs a Private Read to the corresponding Target.
Between these two operations, either STOP + START or Repeated START can be used.

With the current SDK, STOP/START sequence between IBI and Private Read is possible (i.e., the Controller issues a Private Read immediately after receiving the IBI event). Is it possible to implement Repeated START between the IBI and Private Read?

[KDJEM.1 · Accepted solution]

Hello @bell_huang and welcome to the community;

The pending read IBI always ends with STOP. The software then needs to program a read to the target that requested the pending read. No possibility to have a RESTART between the IBI and the private read.

I hope this answer your request!

Than you.

Kaouthar