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

AHB Components3.14 AHB-Lite to AHB wrapperAHB-Lite is a subset of the full AHB specification, and is intended for designs that onlyuse a single bus master. This can either be a simple single-master system or a multi-layerAHB system where there is only one AHB master per layer.Figure 3-32 shows the AHB-Lite to AHB wrapper, Lite2Ahb.AHB-LiteHBURSTS[2:0]HTRANSS[1:0]HPROTS[3:0]HSIZES[2:0]HWRITESHMASTLOCKSHADDRS[31:0]HREADYMUXSHRESPS[1:0]AHB wrapperAHBHBURSTM[2:0]HTRANSM[1:0]HPROTM[3:0]HSIZEM[2:0]HWRITEMHLOCKMHADDRM[31:0]HBUSREQMHREADYMHGRANTMHRESPM[1:0]HCLKHRESETnFigure 3-32 AHB-Lite to AHB wrapper3.14.1 Programmer's modelThe wrapper is designed to enable any AHB-Lite master to connect to a standard AHBbus. This requires the wrapper to add support for the following features:Bus ownershipWhen a transfer is initiated by the master, HTRANSS[1:0] isNONSEQ, the wrapper generates a request using HBUSREQM.The bus is also requested again if ownership is lost mid-burst.Early terminated burstsIf a burst is terminated prematurely through loss of the bus, thewrapper holds the master using HREADYMUXS and rebuildsthe burst when bus control is regained.ARM DDI 0243C Copyright © 2003, 2007 ARM Limited. All rights reserved. 3-65