Other Arm architectures
The Arm architecture is the best known Arm specification, but it is not the only one. Arm has similar specifications for many of the components that make up a modern System-on-Chip (SoC). This diagram provides some examples:
Generic Interrupt Controller
The Generic Interrupt Controller (GIC) specification is a standardized interrupt controller for use with Armv7-A/R and Armv8-A/R.
System Memory Management Unit
A System Memory Management Unit (SMMU or sometimes IOMMU) provides translation services to non-processor masters.
The Generic Timer provides a common reference system count to all the processors in the system. These provide timer functionality, which is used for things like the operating system’s scheduler tick. The Generic Timer is part of the Arm architecture, but the system counter is a system component.
Server Base System Architecture and Trusted Base System Architecture
The Server Base System Architecture (SBSA) and Trusted Base System Architecture (TBSA) provide system design guidelines for SoC developers.
Advanced Microcontroller Bus Architecture
The Advanced Microcontroller Bus Architecture (AMBA) family of bus protocols control how components in an Arm-based system are connected, and the protocols on those connections.