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Re: [lpc2000] Re: Storing in RAM

2005-06-09 by Sridhar gadda

Hi Faurie,
                yes I am using Keil enviornment and thanks for the information. its a great help.
 
regards,
 
Sridhar

Gilles FAURIE <gilles.faurie@...> wrote:
Hello,

You have perhaps Keil envrionment because you use ULINK. If you use KEIL you 
only have to add a #pragma NOINIT before declaration of your variable.
with this your data will keep its value after a reset. If you have a battery 
you won't lose data even if you cut off the power.

For example :

#pragma NOINIT

/* Add your data declaration wich you want to keep value after reset */
BYTE MyData;

#pragma INIT



----- Original Message ----- 
From: "Bill Knight" <BillK@...>
To: <lpc2000@yahoogroups.com>
Sent: Wednesday, June 08, 2005 3:33 PM
Subject: Re: [lpc2000] Re: Storing in RAM


> On Wed, 08 Jun 2005 13:19:51 -0000, soren_t_hansen wrote:
>
>>--- In lpc2000@yahoogroups.com, Sridhar gadda <sridhargadda@y...> wrote:
>>> Hello,
>>>
>>>             I want to write a program which stores a variable in RAM
>>so that when processors get reset, the stored value in RAM should not
>>loose data. Again after reset the processor, I want to read the
>>variable. I am using lpc2129 and ULINK for downlaoding firmware. Can
>>any one suggests me how to proceed ?? does someone encounterd this
>>problem before ??
>>>
>>> I am looking forward to your replies
>>>
>>> best regards,
>>>
>>> Sridhar
>
>>The RAM looses its content in a reset. If you want your program to
>>hold variables after a reset, you have to store them in Flash.
>
>>Best Regards
>>Soren
>
>
> Soren
> Not necessarily.  Static RAM loses it contents on power loss but not
> on processor reset.  Sridhar can accomplish what he desires by
> creating a new memory segment that is not initialized by the processor
> during the boot process and place the desired variables in that memory
> segment.  I would suggest adding a CRC or checksum to confirm the
> values are correct and checking it just after coming out of reset.  If
> the check fails, then default values should be used.  The details of
> creating the memory segment and placing variables are specific to the
> compiler and linker used.
>
> Regards
> -Bill Knight
> R O SoftWare &
> http://www.theARMPatch.com
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
> 




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