TIPS: Keep a variable beetween Resets

RChapman — Wed, 25 Jan 2006 04:52:12 GMT

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Posted: Fri Nov 18, 2005 12:05 pm

Yo People,

If you always wondered how you could keep something in RAM which won't always be re-initialize when you start your code...
Well this is an answer !
You just need to declared a special area in your parameter file and the start-up softawre will not initialize this zone.
It's quite neat if you want to keep a count of the number of resets.

But be careful as if you have a Low Voltage Reset or Power On Reset this value might be corrupted or may not be meaningful.

In the PRM file

Code:

SECTIONS
RESET_COUNTER = NO_INIT 0x1EFF TO 0x1EFF;

Code:

PLACEMENT
NON_INITIALISED INTO EMC_RESET_COUNTER;

And In the C code

Code:

/* global variables */
#pragma DATA_SEG NON_INITIALISED
unsigned char ResetCounter;
#pragma DATA_SEG DEFAULT

Enjoy,

Posted: Fri Nov 18, 2005 4:13 pm

Shouldn't the PLACEMENT be

PLACEMENT
NON_INITIALISED INTO RESET_COUNTER;

instead of

PLACEMENT
NON_INITIALISED INTO EMC_RESET_COUNTER;

Posted: Fri Nov 18, 2005 4:20 pm

is there an error in your PRM? I see a "EMC_RESET_COUNTER" and a "RESET_COUNTER". Are these supposed to be the same? Also, you don't have "DEFAULT" listed in your PRM, but I know what you mean.

Posted: Mon Nov 21, 2005 8:47 am

Yes it should be without the prefix EMC_ on the second time.
I forgot to remove it when I did my copy/paste from my source code.
I did not paste the rest of the prm file (default...) because the prm file is too big for me to paste it in a post.

(bad copy/paste, bad...)

8-bit Microcontrollers中的主题 TIPS: Keep a variable beetween Resets

TIPS: Keep a variable beetween Resets