Preface

monospace

Denotes text that you can enter at the keyboard, such as

 

commands, file and program names, and source code.

monospace

Denotes a permitted abbreviation for a command or option. You

 

can enter the underlined text instead of the full command or option

 

name.

monospace italic

Denotes arguments to monospace text where the argument is to be

 

replaced by a specific value.

monospace bold

Denotes language keywords when used outside example code.

< and >

Angle brackets enclose replaceable terms for assembler syntax

 

where they appear in code or code fragments. They appear in

 

normal font in running text. For example:

 

MRC p15, 0 <Rd>, <CRn>, <CRm>, <Opcode_2>

 

The Opcode_2 value selects which register is accessed.

Timing diagrams

The figure named Key to timing diagram conventions explains the components used in timing diagrams. Variations, when they occur, have clear labels. You must not assume any timing information that is not explicit in the diagrams.

Shaded bus and signal areas are undefined, so the bus or signal can assume any value within the shaded area at that time. The actual level is unimportant and does not affect normal operation.

Clock

HIGH to LOW

Transient

HIGH/LOW to HIGH

Bus stable

Bus to high impedance

Bus change

High impedance to stable bus

Key to timing diagram conventions

xx

Copyright © 2003-2010 ARM Limited. All rights reserved.

ARM DUI 0224I

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Image 20
ARM ARM DUI 0224I manual Timing diagrams