AMBA Introduction

The ARM® AMBA® protocols are an open standard, on-chip interconnect specification for the connection and management of functional blocks in a System-on-Chip (SoC). It facilitates right-first-time development of multi-processor designs with large numbers of controllers and peripherals.

AMBA 5

  • AMBA 5 AHB5 (Advanced High-performance Bus) is the latest addition to the AMBA family, complementing the ARMv8-M architecture to extend the TrustZone security foundation from the processor to the system. 
  • AMBA5 CHI (Coherent Hub Interface) specification adds a new protocol for the interface architecture, highly scalable SoCs required by many server and networking applications.

AMBA 4

  • AMBA 4 AXI and ACE protocol specification adds new optional properties for AXI ordering, ACE cache behavior and ARMv8 DVM messages for full cache coherency between processors.
  • ACE - AXI Coherency Extensions - Used in big.LITTLE™ systems for smartphones, tablets, etc.
  • AXI - Advanced eXtensible Interface - The most widespread AMBA interface. Connectivity up to 100's of Masters and Slaves in complex SoCs.

AMBA 3

  • AHB - Advanced High-Performance Bus - The main system bus in microcontroller usage
  • APB - Advanced Peripheral Bus - Minimal gate count for peripherals
  • ATB - Advanced Trace Bus - For moving trace data around the chip, see CoreSight

Features of AMBA Interfaces

IP re-use is essential in reducing SoC development costs and timescales. AMBA specifications provide interface standards that enables IP re-use if the following essential requirements are met:

Flexibility

IP re-use requires a common standard while supporting a wide variety of SoCs with different power, performance and area requirements. With its ACE, AXI, AHB and APB interface protocols, AMBA 4 has the flexibility to match every requirement. With AMBA 5 CHI interface ARM extends performance and scalability to many coherent processors.

Wide Adoption

There is a large amount of IP available in the industry today. AMBA caters for this IP and engineers across the globe have accepted it as a standard and use it daily. It is the most widely adopted industry standard for on-chip connectivity for IP products varying from; Memory Controllers, Interconnects, Trace solutions, GPU's, CPU's

Compatibility

It is a standard interface specification that ensures compatibility between IP components from different design teams or vendors. The AMBA specifications are available as both a written specification as well as a set of assertions that unambiguously define the interface protocol, thus ensuring this level of compatibility.

Support

The wide adoption of AMBA specifications throughout the semiconductor industry has driven a comprehensive market in third party IP products and tools to support the development of AMBA based systems. The availability of SystemVerilog assertions for AMBApromote this industry wide participation.