SPRUIL1D May 2019 – December 2024 DRA829J , DRA829J-Q1 , DRA829V , DRA829V-Q1 , TDA4VM , TDA4VM-Q1
The Translation Control Unit (TCU) reads a stream of DTI-protocol translation requests from the distributed TBUs and returns translation information either from the TCU's local cache or from tables in memory. The TCU is wrapped in a module that includes the CBASS transaction push and pull interfaces. TCU operations that require table walking use these interfaces to access DDR memory where the in-memory page tables are stored.
Additionally, TCU handles Address Translation Service (ATS) for PCIe and the equivalent function for USB.
The K3 architecture does not support hardware coherence between any cached page table information in the TCU and operations on memory from the compute cluster. If an agent in the compute cluster modifies page tables, some mechanism must be used to initiate TCU invalidation. TCU invalidations automatically handle the subsequent TBU invalidations. This behavior is consistent with the Arm SMMU system architecture definition.
Figure 8-16 TCU Functional Diagram