37.2.7.2.11 Set/Get Maximum Write Length (SETMWL/GETMWL)

The Controller uses the Direct and Broadcast SETMWL CCC to set the maximum data write length for the Target, which is stored in the I3CxMWL register and is updated after the entire CCC has been processed.

The Controller uses the Direct GETMWL CCC to read the maximum data write length from the Target. This CCC transmits the I3CxMWL register from the Target with the Most Significant bit first.

The frame format for Direct SETMWL/GETMWL CCC is shown in Figure 37-37, whereas the frame format for the Broadcast SETMWL is shown in Figure 37-38.

Refer to the Private Write Transaction section to learn about the significance of Maximum Write Length.

Important:
  1. As per the MIPI I3C® Specification v1.1.1, the minimum I3CxMWL Maximum Write Length value the Controller can set is 16 bytes.
  2. The value of the I3CxMWL register can also be changed by software write in addition to the Controller writing using the SETMWL CCC. It is highly recommended for the user to change the value of this register when there are no transactions happening on the bus. In case of a race condition, user writes take precedence over SETMWL CCC.
Figure 37-37. Direct Write/Read SETMWL/GETMWL Frame Format
Figure 37-38. Broadcast Write SETMWL Frame Format