Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 11/27/2024
Public
Document Table of Contents

12.2.6.3. AxUSER Bit Connectivity

The F2H and F2SDRAM ports support read and write stream IDs (SID) and secure state determination (SSD) signals as a hint to the respective TBU as to what translations must be performed for the current transactions. The FlexNoC does not directly support these signals as part of the AXI protocol, therefore they must be transported through the MPFE NoC as AxUSER signals.

The MPFE NoC supports masterID based firewalls to grant access to regions of SDRAM by both the FPGA fabric and HPS masters. Therefore, the AxUSER signals from the CCU must also be brought into the MPFE NoC.

By convention, accesses from F2SDRAM:

  • AxUSER[7:0] must be set to 0xE0
  • AxUSER[8] = 1, then AxPROT settings are used to determine security
  • AxUSER[8] = 0, then AxPROT settings are overridden, and transactions are non-secure

By convention, accesses from F2H:

  • AxUSER[7:0] = 0x04
Note: This convention maintains backward compatibility with previous families with regard to dynamic transaction routing.
The following figure shows the connectivity of the SID and SDD for both the F2SDRAM and F2H ports. The number of FPGA fabric masters in this figure is only an example configuration to show that more than one master can be attached to the port.
Figure 297. SID and SSID FPGA Fabric Example Configuration