SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
Figure 14-10 is an internal view of the L4 interconnects in the overall interconnect. This architecture, with one initiator subsystem centralizing all initiator master requests and distributing them to all target modules (peripherals), enables the L4 interconnect firewall functions to be centralized at the L4 initiator subsystem level. The L4 firewall filters the accesses based on the configurable protection groups defined in the L4 address protection (AP) registers. Each module or TA is assigned to a protection group. The configuration is also defined in the L4 AP and is programmable on a module-per-module basis.
As Figure 14-10 shows, targets are attached to branches. Branches do not impact the function of the L4 interconnect but are present to simplify timing closure and reduce active power consumption.
Because of the large address spaces and the number of peripherals connected to an L4 interconnect, two parameters are used to set up access permission:
Protection group members are TAs with the same protection settings. A region is programmed to allow access to a unique selectable protection group. For better protection, different regions are grouped into protection group regions and associated with a protection group member.