Bus Interface Unit
6-2
Copyright © 2000 ARM Limited. All rights reserved.
ARM DDI 0186A
6.1
About the BIU and write buffer
The ARM966E-S supports an Advanced Microprocessor Bus Architecture (AMBA)
Advanced High-performance Bus (AHB) interface. The AHB is a new generation of
AMBA interface that addresses the requirements of high-performance synthesizable
designs, including:
•
single clock edge operation (rising edge)
•
unidirectional (nontristate) buses
•
burst transfers
•
split transactions
•
single-cycle bus master handover.
See the
AMBA Rev 2.0 AHB specification
for full details of this bus architecture.
The ARM966E-S BIU implements a fully-compliant AHB bus master interface and
incorporates a write buffer to increase system performance. The BIU is the link between
the ARM9E-S core with its tightly-coupled SRAM and the external AHB memory. The
AHB memory must be accessed to initialize the tightly-coupled SRAM. The AHB
memory must also be accessed to access code and data that are not assigned to the
tightly-coupled SRAM address space (or if the SRAM is disabled).
When an external AHB access is performed, the BIU and the system controller
handshake to ensure that the ARM9E-S core is stalled. If the write buffer is used, it
might be possible to allow the core to continue program execution. The BIU is
responsible for controlling the write buffer and related stall behavior (see
Содержание ARM966E-S
Страница 6: ...Contents vi Copyright 2000 ARM Limited All rights reserved ARM DDI 0186A ...
Страница 20: ...Introduction 1 4 Copyright 2000 ARM Limited All rights reserved ARM DDI 0186A ...
Страница 48: ...Tightly coupled SRAM 4 12 Copyright 2000 ARM Limited All rights reserved ARM DDI 0186A ...
Страница 80: ...Bus Interface Unit 6 20 Copyright 2000 ARM Limited All rights reserved ARM DDI 0186A ...
Страница 118: ...Debug Support 8 26 Copyright 2000 ARM Limited All rights reserved ARM DDI 0186A ...
Страница 130: ...Test Support 10 8 Copyright 2000 ARM Limited All rights reserved ARM DDI 0186A ...
Страница 142: ...Instruction cycle timings 11 12 Copyright 2000 ARM Limited All rights reserved ARM DDI 0186A ...
Страница 158: ...Signal Descriptions A 16 Copyright 2000 ARM Limited All rights reserved ARM DDI 0186A ...
Страница 176: ...AC Parameters B 18 Copyright 2000 ARM Limited All rights reserved ARM DDI 0186A ...