Motorola MVME2600 Series Programmer's Reference Manual page 18

Board Description and Memory Maps
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Unless otherwise specified, all address references are in
hexadecimal.
An asterisk (*) following the signal name for signals which are level
significant denotes that the signal is true or valid when the signal is
low.
An asterisk (*) following the signal name for signals which are edge
significant denotes that the actions initiated by that signal occur on
high to low transition.
Note In some places in this document, an underscore (_)
following the signal name is used to indicate an active
low signal.
In this manual, assertion and negation are used to specify forcing a
signal to a particular state. In particular, assertion and assert refer
to a signal that is active or true; negation and negate indicate a
signal that is inactive or false. These terms are used independently
of the voltage level (high or low) that they represent.
Data and address sizes for MPC60x chips are defined as follows:
A byte is eight bits, numbered 0 through 7, with bit 0 being the
least significant.
A half-word is 16 bits, numbered 0 through 15, with bit 0 being
the least significant.
A word or single word is 32 bits, numbered 0 through 31, with
bit 0 being the least significant.
A double word is 64 bits, numbered 0 through 63, with bit 0
being the least significant.
Refer to Chapter 5 for Endian Issues, which covers which parts of the
MVME2600 series use big-endian byte ordering, and which use
small-endian byte ordering.
The terms control bit and status bit are used extensively in this
document. The term control bit is used to describe a bit in a register
that can be set and cleared under software control. The term true is