A.1. About AHB-Lite

AHB-Lite is a subset of the full AHB specification and is intended for use in designs where 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 AHB master per layer.

Figure A.1. AHB-Lite single-master system

AHB-Lite simplifies the AHB specification by removing the protocol required for multiple bus masters, and includes:

Masters designed to the AHB-Lite interface specification can be significantly simpler in terms of interface design, compared to a full AHB master. AHB-Lite enables faster design and verification of these masters and the addition of a standard off-the-shelf bus mastering wrapper can be used to convert an AHB-Lite master for use in a full AHB system.

Any master that is already designed to the full AHB specification can be used in an AHB-Lite system with no modification.

The majority of AHB slaves can be used interchangeably in either an AHB or AHB-Lite system. This is because AHB slaves that do not use either the SPLIT or RETRY response are automatically compatible with both the full AHB and the AHB-Lite specification. It is only existing AHB slaves that do use SPLIT and RETRY responses that require an additional standard off-the-shelf wrapper to be used in an AHB-Lite system.

Any slave designed for use in an AHB-Lite system works in both a full AHB and an AHB-Lite design.

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