Derek Fritz

Specifying the global address for a variable using the MC9S12XS128

Discussion created by Derek Fritz on Sep 29, 2009
Latest reply on Oct 2, 2009 by Xbot

Hello,

 

I'm trying to assign variables to specific global addresses in the MC9S12XS128 data flash memory structure.  So far, I've only been able to successfully do this using the local address space, such as the following:

 

     extern uword EE_VERSION             @(0x0800); 

 

This assignment works fine, and I can see the location in memory using both the logical and global memory views in the debugger.

 

However, if I try to allocate the variable to the corresponding global address:

 

     extern uword EE_VERSION             @(0x100000);

 

I receive the following message: "L4100: Failed to convert address 0x100000 of In debug info because of 'Register area (0..7FF) is not paged"

 

Is there any way to correctly do this, or can I only assign variables to a local address and then do some type of conversion to the global address when manipulating the EEPROM? 

 

How would the compiler know which page I'm assigning the variable to if this is the case?  Does the EPAGE register need to be utilized in conjunction with assignments such as this?

 

Any help would be much appreciated.  Regards.

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