The CCCs are the commands that an I3C Master uses to communicate to some or all of the Slaves on the I3C Bus. The CCCs are sent to the I3C Broadcast address (which is 7’h7E) so as not to interfere with normal messages sent to a Slave. In other words, CCCs are separated from the standard “content protocol” used by normal messages, such as Private Write and Read transfers (in SDR Mode).
The CCCs are used for standard operations like enabling/disabling events, managing I3C‑specific features, and other Bus operations. CCCs can be either Broadcasted (i.e., sent to all Devices on the I3C Bus), or else Directed at specific Devices on the I3C Bus. All CCCs (i.e., the command numbers themselves) are allocated by MIPI Alliance, and some are reserved for specific purposes including MIPI Alliance enhancements and other extensions.