AMBA Design Kit Technical Reference Manual - ARM Information ...

AHB-Lite OverviewA.1 About AHB-LiteAHB-Lite is a subset of the full AHB specification and is intended for use in designswhere only a single bus master is used. This can either be a simple single-master system,as shown in Figure A-1, or a multi-layer AHB system where there is only one AHBmaster per layer.Slave 1MasterSlave 2Slave 3Figure A-1 AHB-Lite single-master systemAHB-Lite simplifies the AHB specification by removing the protocol required formultiple bus masters, and includes:• request and grant protocol to the arbiter• SPLIT and RETRY responses from slaves.Masters designed to the AHB-Lite interface specification can be significantly simplerin terms of interface design, compared to a full AHB master. AHB-Lite enables fasterdesign and verification of these masters and the addition of a standard off-the-shelf busmastering wrapper can be used to convert an AHB-Lite master for use in a full AHBsystem.Any master that is already designed to the full AHB specification can be used in anAHB-Lite system with no modification.The majority of AHB slaves can be used interchangeably in either an AHB or AHB-Litesystem. This is because AHB slaves that do not use either the SPLIT or RETRYresponse are automatically compatible with both the full AHB and the AHB-Litespecification. It is only existing AHB slaves that do use SPLIT and RETRY responsesthat require an additional standard off-the-shelf wrapper to be used in an AHB-Litesystem.Any slave designed for use in an AHB-Lite system works in both a full AHB and anAHB-Lite design.A-2 Copyright © 2003, 2007 ARM Limited. All rights reserved. ARM DDI 0243C