Advanced Microcontroller Bus Architecture

Advanced Microcontroller Bus Architecture

The Advanced Microcontroller Bus Architecture (AMBA) is used as the on-chip bus in system-on-a-chip (SoC) designs. Since its inception, the scope of AMBA has gone far beyond microcontroller devices, and is now widely used on a range of ASIC and SoC parts including applications processors used in modern portable mobile devices like smartphones.

The AMBA protocol is 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 was introduced by ARM Ltd in 1996. The first AMBA buses were Advanced System Bus (ASB) and Advanced Peripheral Bus (APB). In its 2nd version, AMBA 2, ARM added AMBA High-performance Bus (AHB) that is a single clock-edge protocol. In 2003, ARM introduced the 3rd generation, AMBA 3, including AXI to reach even higher performance interconnect and the Advanced Trace Bus (ATB) as part of the CoreSight on-chip debug and trace solution. These protocols are today the de facto standard for 32-bit embedded processors because they are well documented and can be used without royalties.