Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 7/19/2024
Public
Document Table of Contents

5.8.6.5.3.1. SIR Response Control

  1. In the secondary master configuration, the controller handles the SIR response to the targeted slave through a 32-bit vector control register (IBI_SIR_REQ_REJECT). This register is used to control the response individually for each I3C slave device. Each bit field of the control register is mapped to a unique 7-bit slave device address through the modular arithmetic operation as shown in the following figure:

    The sum of the lower 5 bits and the upper 2 bits of the slave interrupt request ID (dynamic address of the requesting slave) is wraparound upon reaching the value 32 (module 32) to uniquely map the bit position of the 32-bit control register.

  2. In the master-only configuration, the controller handles the SIR response to the targeted slave through the SIR_REJECT control of the corresponding DAT entry.

If SIR response control is set to 1, then the controller NACKs the SIR and then issues a directed DISEC CCC command (DISINT bit set) with the RESTART condition targeting the matching dynamic address. This disables the SIR generation in the requested slave device. The IBI status for the corresponding SIR indicates to the application that the incoming IBI is NACK’d through ‘IBI_STS’ descriptor.

If SIR response control is set to 0, then the controller ACKs the SIR. If the IBI Payload Control is set to 1, then the controller continues to generate the SCL clocks after the ACK to accept the IBI payload bytes starting from the MDB until the slave device terminates the transfer. The application must set the IBI Payload Control to 1 only when the slave device supports the mandatory byte (BCR[2]=1). If the IBI Payload Control is set to 0, then the controller stops generating the SCL clock after acknowledging the SIR. The controller then notifies the application to take necessary action for the accepted SIR. The application must not set the IBI Payload Control bit to 1 when the slave device does not support the mandatory data byte (BCR[2]=0).

In master-only configurations, if the received IBI ID (SIR) does not match with any of the dynamic address entries of the DAT table, then the controller sends a NACK response and generates IBI status to the application. The controller does not send any disable event command and expects the application to take necessary action if the unknown device repeatedly interrupts. In this case, the generation of IBI status is independent of the SIR reject notify control settings.