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ARM advanced microcontroller bus architecture (AMBA) specification.Rev 2.0.pdf
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AMBA AHB

3.1About the AMBA AHB

AHB is a new generation of AMBA bus which is intended to address the requirements of high-performance synthesizable designs. AMBA AHB is a new level of bus which sits above the APB and implements the features required for high-performance, high clock frequency systems including:

burst transfers

split transactions

single cycle bus master handover

single clock edge operation

non-tristate implementation

wider data bus configurations (64/128 bits).

3.1.1A typical AMBA AHB-based microcontroller

An AMBA-based microcontroller typically consists of a high-performance system backbone bus, able to sustain the external memory bandwidth, on which the CPU and other Direct Memory Access (DMA) devices reside, plus a bridge to a narrower APB bus on which the lower bandwidth peripheral devices are located. Figure 3-1 shows both AHB and APB in a typical AMBA system.

 

 

High-performance

 

High-bandwidth

 

 

 

 

 

 

 

 

 

 

ARM processor

 

on-chip RAM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B

 

UART

 

Timer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

AHB

 

 

R

 

 

 

 

 

 

High-bandwidth

 

 

 

 

 

 

 

APB

 

 

 

 

 

 

 

 

 

 

 

I

 

 

 

 

Memory Interface

 

 

 

 

 

 

 

 

 

D

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

G

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

E

 

Keypad

 

PIO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DMA bus

 

 

 

 

 

 

 

 

 

 

 

 

 

 

master

AHB to APB Bridge

 

 

 

 

 

AMBA Advanced High-performance Bus (AHB)

AMBA Advanced Peripheral Bus (APB)

* High performance

 

 

* Low power

 

 

 

 

 

 

* Pipelined operation

 

 

* Latched address and control

 

 

* Burst transfers

 

 

* Simple interface

 

 

* Multiple bus masters

 

 

* Suitable for many peripherals

 

 

* Split transactions

 

 

 

 

 

 

 

 

 

 

 

Figure 3-1 A typical AMBA AHB-based system

ARM IHI 0011A

© Copyright ARM Limited 1999. All rights reserved.

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