Translation table walks
When the Cortex®‑A76 core generates a memory access, the MMU:
- Performs a lookup for the requested VA, current ASID, current VMID, and current translation regime in the relevant instruction or data.
- If there is a miss in the relevant L1 TLB, the MMU performs a lookup for the requested VA, current ASID, current VMID, and translation regime.
- If there is a miss in the L2 TLB, the MMU performs a hardware translation table walk.
In the case of a L2 TLB miss, the hardware does a translation table walk as long as the MMU is enabled, and the translation using the base register has not been disabled.
If the translation table walk is disabled for a particular base register, the core returns a Translation Fault. If the TLB finds a matching entry, it uses the information in the entry as follows.
The access permission bits determine if the access is permitted. If the matching entry does not pass the permission checks, the MMU signals a Permission fault. See the Arm® Architecture Reference Manual Armv8, for Armv8-A architecture profile for details of Permission faults, including:
- A description of the various faults.
- The fault codes.
- Information regarding the registers where the fault codes are set.
This section contains the following subsection: