37.2.4.2.1 I2C Static Address
Every device on the I3C bus has a 7-bit Static Address that the device uses to communicate on the bus before it is assigned a Dynamic Address. This Target module stores the Static Address in the I3CxSADR register. The user must configure this Static Address during setup before the module is enabled for proper operation.
The Target module operates in I2C mode (OPMD =
0b00) using this Static Address after it is set up
and enabled until it is assigned a Dynamic Address by the Controller or the Static
Address SDR mode is activated.(2) While the Target is operating in I2C mode, the Controller
can engage with the Target through a legacy I2C read/write transaction. Refer
to Legacy
I2C Transaction on I3C Bus for more information.Since the I2C protocol does not support address arbitration, the Static
Address is not arbitrable, meaning only the Controller can drive the Target’s Static
Address on the bus when writing to (R/W bit =
0) or reading from (R/W bit =
1) the Target. When operating in I2C mode, the Target
sets the SADRIF interrupt flag when it detects the Controller has
transmitted the Target’s Static Address on the bus. Table 37-6 shows the different conditions when this Target module
ACK/NACKs the static address on the bus.The Controller usually communicates at slower I2C speeds when communicating with an I2C device (or I3C devices operating in I2C mode) on the bus.
Important:
- The Target typically cannot drive the address on the bus in I2C mode with the exception of making a Hot-Join request, in which case it transmits the reserved I3C Hot-Join Address.
- This Target device supports a
special Static Address SDR Mode where the module can operate in I3C SDR mode
(OPMD =
0b01) using its Static Address without requiring a Dynamic Address. Refer to Static Address SDR Mode for more information. A Static Address match in this mode also sets the SADRIF bit. It is imperative to note that when operating in this mode, the Static Address following a Start (but not a Restart) is also arbitrable.