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

AHB ComponentsTable 3-10 describes the extra signals declared in the AhbToApb bridge including theAPB 3.0 signals.Signal Direction DescriptionTable 3-10 AhbToAPB Bridge signalsPSEL Output Select. It indicates that an APB slave is selected and a datatransfer is required. PSEL is a combined select output,when HIGH indicates that an APB slave is selected andthat a data transfer is required. You can use this signal asan input to an external address decoder.PREADY Input Ready. The APB slave uses this signal to extend an APBtransfer.PSLVERR Input This signal indicates a transfer failure and is driven by theAPB peripheral.NoteTiming diagrams showing the relationship between AHB and APB 3.0 transfers are inthe AMBA 3 APB Protocol Specification.ARM DDI 0243C Copyright © 2003, 2007 ARM Limited. All rights reserved. 3-43