Lpc2000

Quoting raweaver06 <raweaver00@...>:

> I'm looking into using ARM so I'm a newbie.  I currently use a
> processor that is 16 bits 30MIPS capable.  So seeing that ARM is 32
> bits and 60 MIPS capable has me wanting.  I've read that real world is
> actually 52 MIPS (still above my baseline 30 MIPS).  But then I've seen
> where you have to run 1/4 speed out of FLASH.  So is the 52 MIPS number
> just running out of RAM?  I'll need most of my RAM for application so I
> want the program to stay in FLASH.  Does running out of FLASH mean 52/4
> for only 13 MIPS thruput.  I might as well stay with my current
> processor if so.  I might as well stop reading all of this ARM
> documentation if this is true.

A couple of things to point out.

Throughput and MIPS are quite different things. A 32 bit ARM at 60 MIPs will
handle 32 bit arithmetic quite a bit faster than a 16 bit processor at 
30 MIPs.
Throughput (moving data to/from peripherals and I/O) depends highly on the
implementation of the peripherals and items like DMA and Psuedo DMA.  In
particular I/O bit twiddling is not an ARMs strong suit.

On the LPC running ARM code out of flash with the flash acceleration options
turned on you get pretty close to full speed.  On other implementations code
running out of flash will be slower simply because the flash is slower 
or has a
16 bit interface.  Running out of RAM also runs at full speed.

The 52 MIPs number is I think for running thumb code which is prefered by some
for being more compact.  On implementations with 16 bit wide flash interfaces
it will also speed up execution since only one memory acces needs to be done
for each instruction fetch (not true for LPCs though).

That's either helped or I've confused you even more. :)

Robert