In I3C v1.1.1 and I3C Basic v1.1.1, a new dummy command code value 0x1F is defined for special use only in CCC flows for HDR Modes that require special structured protocol elements (i.e., Words or Blocks) to conform to that HDR Mode’s coding. This 0x1F dummy command code has no meaning as a standard CCC. But in such special flows, it takes the place of a valid CCC and is used in a valid End-of-CCC Procedure to signal the end of CCC modality and return to that HDR Mode’s standard generic HDR Write and Read transfers. Dummy command code 0x1F is currently used solely in HDR-DDR Mode, where every HDR-DDR Write must include at least one HDR-DDR Data Word.
Note: In I3C v1.1, the equivalent End-of-CCC Procedure was incorrectly defined. Errata 01 for I3C v1.1 addresses this with an updated definition using this dummy command code. Implementers should use only the updated definition in Errata 01 (or newer), or in I3C v1.1.1 (or newer). See Q4.4, "Are there any impending fixes or errata for MIPI I3C v1.1 that should be applied now?".
Dummy command code 0x1F may not be used in SDR Mode, nor in any HDR Modes other than HDR-DDR Mode. Dummy command code 0x1F has no meaning as a standard CCC.