Some of the CISC processors like the Intel x86
series and some of the MC68k series CPU automtaically
take care of odd boundary reads (especially on double words),
but at a huge loss in processing time.
The DragonBall is like most embedded CPU chips
that does not handle this since it takes many extra CPU
cycles to handle it which can be spent more effectively on
other things. Thus, these CPUs rely on both the programmer
and the compiler to make shure that all data and adressing
is handled on word boundaries. This includes the PowerPC
series, the MVxxx series from Motorola, the ARM chips,
and the notorious i960 series from Intel.
All of these chips are used in embedded applications from cell
phones to dgital cameras to PDAs.
Keeping the CPU from having to wory about boundary issues
makes it process much faster with little cost to the clock.
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Jimi
Malcolm
Sent: Tuesday, July 03, 2001 4:22 PM
To: Palm Developer Forum
Subject: Why're address errors so bad?
I know an address error is accessing a 2- or 4-byte value at an odd memory
address (as the POSE debugger tells me).
Why is it so bad?
--
Jimi Malcolm
Web Content Manager
inburst Internet Media
inburst.com
jimi.malcolm@inburst
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