SMC Networks AHB SRAM/NOR, PL241 manual AHB interface, AHB to APB bridge

Models: AHB SRAM/NOR PL241

1 110
Download 110 pages 44.4 Kb
Page 17
Image 17
1.1.1AHB interface

Introduction

1.1.1AHB interface

The interface converts the incoming AHB transfers to the protocol used internally by the AHB MC.

The interface has the following features:

all AHB fixed length burst types are directly translated to fixed length bursts

all undefined length INCR bursts are converted to INCR4 bursts

broken bursts are supported

the bufferable bit of the HPROT signal determines if the interface must wait for a write transfer to complete internally

a Read After Write (RAW) hazard detection buffer avoids RAW hazards

AHB response signals are registered to improve timing

locked transfers are supported within a 512MB region

HWDATA is registered to improve internal timing paths

a big-endian 32-bit mode option is implemented

AHB error response logic is removed as no internal components generate errors.

This interface is a fully validated component. This ensures that it obeys both the AHB protocol and the internal protocol that the interconnect uses.

See Chapter 2 Functional Overview for more information.

1.1.2AHB to APB bridge

This bridge converts AHB transfers from the configuration port to the APB transfers that the internal memory controllers require.

See Chapter 2 Functional Overview for more information.

ARM DDI 0389B

Copyright © 2006 ARM Limited. All rights reserved.

1-3

Page 17
Image 17
SMC Networks AHB SRAM/NOR, PL241 manual AHB interface, AHB to APB bridge