ARM ARM926EJ-S Technical Reference Manual page 234

Glossary
Exception
Exception service routine
Exception vector
External Abort
Fast context switch
Fast Context Switch Extension (FCSE)
FCSE
Flat address mapping
Glossary-10
A fault or error event that is considered serious enough to require that program
execution is interrupted. Examples include attempting to perform an invalid memory
access, external interrupts, and undefined instructions. When an exception occurs,
normal program flow is interrupted and execution is resumed at the corresponding
exception vector. This contains the first instruction of the interrupt handler to deal with
the exception.
See Interrupt handler.
See Interrupt vector.
An indication from an external memory system to a core that it must halt execution of
an attempted illegal memory access. An External Abort is caused by the external
memory system as a result of attempting to access invalid memory.
See also Abort, Data Abort and Prefetch Abort.
In a multitasking system, the point at which the time-slice allocated to one process stops
and the one for the next process starts. If processes are switched often enough, they can
appear to a user to be running in parallel, as well as being able to respond quicker to
external events that might affect them.
In ARM processors, a fast context switch is caused by the selection of a non-zero PID
value to switch the context to that of the next process. A fast context switch causes each
Virtual Address for a memory access, generated by the ARM processor, to produce a
Modified Virtual Address which is sent to the rest of the memory system to be used in
place of a normal Virtual Address. For some cache control operations Virtual Addresses
are passed to the memory system as data. In these cases no address modification takes
place.
See also Fast Context Switch Extension.
An extension to the ARM architecture that enables cached processors with an MMU to
present different addresses to the rest of the memory system for different software
processes, even when those processes are using identical addresses.
See also Fast context switch.
See Fast Context Switch Extension.
A system of organizing memory in which each Physical Address contained within the
memory space is the same as its corresponding Virtual Address.
Copyright © 2001-2003 ARM Limited. All rights reserved. ARM DDI0198D