APU Memory Management Unit

Zynq UltraScale+ Device Technical Reference Manual (UG1085)

Document ID
UG1085
Release Date
2022-09-15
Revision
2.3 English

In the AArch32 state, the Arm v8 address translation system resembles the Arm v7 address translation system with large physical-address extensions (LPAE) and virtualization extensions.

In AArch64 state, the Arm v8 address translation system resembles an extension to the long descriptor format address translation system to support the expanded virtual and physical address spaces. For more information regarding the address translation formats, see the Arm® Architecture Reference Manual Arm v8, for the Arm v8-A architecture profile.

The memory management unit (MMU) controls table-walk hardware that accesses translation tables in main memory. The MMU translates virtual addresses to physical addresses. The MMU provides fine-grained memory system control through a set of virtual-to-physical address mappings and memory attributes held in page tables. These are loaded into the translation lookaside buffer (TLB) when a location is accessed.

Address translations can have one or two stages. Each stage produces output LSBs without a lookup. Each stage walks through multiple levels of translation. This Figure and This Figure show an example block translation and a page translation, respectively.

Figure 3-3:      Block Translation

X-Ref Target - Figure 3-3

X16949-block-translation.jpg
Figure 3-4:      Page Translation

X-Ref Target - Figure 3-4

X16950-page-translation.jpg