I3C Controller Devices that comply with the MIPI I3C Host Controller Interface specification (i.e., I3C HCI  v1.0 [MIPI02] or v1.1 [MIPI13]) can easily support Pending Read Notifications. MIPI I3C HCI already defines a standard feature known as “Auto-Command” that conforms to the Pending Read Notification  contract and enables (in SDR Mode) automatic initiation of Private Reads or (in supported HDR Modes) Generic Reads in hardware, without software intervention, based on matching MDB values in IBIs received from I3C Target Devices.

Implementers of other I3C Controller Devices could choose to offer support for Pending Read Notifications as a feature in hardware and/or firmware, with varying degrees of configurability. In situations where hardware or firmware support is not feasible, an I3C Controller Device and its Host could also support this in software, provided that the Host’s software upholds all the expectations in the Pending Read Notification contract (see specification Section 5.1.6.2.2). Note that this may require the ability to pause or cancel any previously enqueued Read transfers if the I3C Controller receives such an IBI with matching MDB value to signal a Pending Read Notification, as this would oblige the I3C Controller or its Host to initiate a Read (i.e., SDR Private Read or HDR Generic Read) that is expected for this particular IBI.

FAQ Type: 
I3C