"DIAMOND JEFF" <[EMAIL PROTECTED]> wrote in message
news:38070@palm-dev-forum...
>
> I know this is highly likely, but since a lot of ARM cores (especially
> early on) didn't support 16-bit numbers, and since I've learned not to
> assume anything, I wondered if Palm will be using ARMs with 16-bit
> number support?
Palm stated that they will support the ARM 4T architecture, which is used in
the ARM7, and is supported by ARM9 and XScale/StrongARM. This includes
16-bit data access instructions that do either zero or sign extension. The
development board they showed PalmOS 3.5 running on was using a ARM7
core-based chip from Cirrus Logic. They did say they were not going to
support Thumb, which is a 16-bit variant of the ARM instruction set
implemented on some ARM chips -- its main use is on memory constrained
systems and 8/16 bit bus systems, so that points to them using a 32-bit bus
to memory; otherwise, they would have a major bottleneck in instruction
fetching.
BTW, you can download the current ARM architecture manual, including the
complete instruction set, from www.arm.com. Just go to the "technical
support" section, and follow the links to documentation. The current ARM
Architecture Reference Manual, 2nd edition, just was published in December,
is over 800 pages, and seems to consistently be around $55 at any of the
online book stores that carry it.
--
Ben Combee
Veriprise Wireless <http://www.veriprise.com>
--
For information on using the Palm Developer Forums, or to unsubscribe, please see
http://www.palmos.com/dev/tech/support/forums/
