Lpc2000

You can look up the functions of the MAMCR(0xE01FC000) and
MAMTIM(0xE01FC004) registers in the User Manual to see how wait states
are configured, but the RESET state is to have the MAM disabled. I can
not tell from reading the register descriptions if all 6 wait states
are enabled if MAMCR is all zeros, OR if there are no wait states
enabled if MAMCR is disabled. I have always cofigured access times
according to clock speed like the manual suggests, so I can't come up
with an answer from personal experience. The safe default is to come
out of RESET with the maximum number of wait states enabled, but I can
not find that statement in the manual, so it is only a guess that
probably you are running with 6 wait states ( 7 clocks access). Since
you are successfully running the clock at 48MHz, you either have a
VERY fast part, or your are running with some wait states, since 20MHz
is the maximum for single clock access to the internal FLASH according
to the MAM usage notes.
--Dave


-- In lpc2000@yahoogroups.com, ayman ghaly <ghalyayman@...> wrote:
>
> Thanks Dav for your concern.
>   I download the program to the internal flash of the ARM board, so
I don't use external memory. I didn't find anything related to the
number of wait states in the manual of the LPC2129 regarding to this.
>   Ayman
>   
> 
> derbaier <dershu@...> wrote:
>   
> How many wait states did you have on your real physical memory and how
> many wait states did you tell your simulator to simulate?
> 
> -- Dave
> 
> --- In lpc2000@yahoogroups.com, ayman ghaly <ghalyayman@> wrote:
> >
> >   Hi all
> > 
> >     I measured the execution time of the code shown below using
> break points in the keil simulator and it was approximately 500 micro
> seconds. 
> >   But when I measured the execution time of the same code from the
> Philips ARM board LPC2129 it was about 3000 micro seconds.
> >   Do you have any idea about the cause of this difference?
> >    
> >   Note that I used the following adjustments before running the code:
> >   Target: Philips LPC2129
> >   Oscillator frequency: 12 MHz
> >   CCLK= 48MHz
> >   PCLK= CCLK/2
> >   Cc: No optimization for the code
> >    
> >   Code:
> >    
> >    
> >               unsigned int i,j;
> >               for (i=0;i<5;i++)
> >                           {
> >                           for (j=0;j<286;j++);  
> >                           }
> >    
> >   Thanks for your help.
> >   Ayman
> > 
> > 
> >             
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