Preface 
ARM DDI0198D Copyright © 2001-2003 ARM Limited. All rights reserved. xix
Key to timing diagram conventions
Signal naming
The level of an asserted signal depends on whether the signal is active-HIGH or 
active-LOW. Asserted means HIGH for active-HIGH signals and LOW for active-LOW 
signals:
Prefix H  Denotes Advanced High-performance Bus (AHB) signals.
Prefix n  Denotes active-LOW signals except in the case of AHB or Advanced 
Peripheral Bus APB reset signals. These are named HRESETn and 
PRESETn respectively.
Prefix DH  Denotes data side AHB signals.
Prefix IH  Denotes instruction side AHB signals.
Prefix DR  Denotes data side TCM interface signals.
Prefix IR  Denotes instruction side TCM interface signals.
Prefix ETM  Denotes ETM interface signals.
Prefix DBG  Denotes debug/JTAG signals.
Prefix CP  Denotes coprocessor interface signals.
Clock
HIGH to LOW
Transient
HIGH/LOW to HIGH
Bus stable
Bus to high impedance
Bus change
High impedance to stable bus