There are several types and sizes of on-chip, embedded memory.
- PPU RAM
- PMC RAM
- RPU tightly-coupled memory (TCM)
- APU L2-cache memory
The PPU RAM is 384 KB with ECC protection. The memory is used for the platform loader and manager (PLM) firmware code and data structures. It is normally only accessed by the PLM.
The PMC RAM is 128 KB with ECC protection. The PMC_RAM memory is used by the PLM to store shared data structures and other purposes. It is accessible to any transaction host with access privileges. It is protected by the PMC_XMPU protection unit.
RPU Tightly-Coupled Memory
The RPU includes 256 KB of memory tightly couple memory (TCM) for predictable access latency to the Cortex-R5F processors. The TCM is divided into 6 banks with parallel interconnect to the processors. The TCM banks are described in Tightly-coupled Memories.
APU L2-Cache Memory
The APU Cortex-A72 MPCore includes a 1 MB L2-cache that can be shared with processor in the PL with its own L2 cache using two-way coherency/snoop activities. The L2 cache is coupled with the CCI and SMMU to provide memory sharing and virtualization. The L2-cache is part of the APU.