CW 4.7 XEP100, why is ROM_4000 not used?

[AndersJ]

When a project is created, ROM_4000 is defined but not placed, in the prm file.

When Processor Expert is used, ROM _4000 is not mentioned at all.

Why is ROM_4000 not used in XEP100 projects?

Anders J

[ProcessorExpert]

Hello,

reagrding PEx. Did you enable the appropriate segment on build options tab in CPU component?

best regards
Vojtech Filip
Processor Expert Support Team

[AndersJ]

Yes, I have enabled it, and placed all default sections that "normally"

go into ROM_C000, also in ROM_4000, and it seems OK.

SInce it seems to work, this is the reason I am asking.

Why is ROM_4000 not available by default?

Are there any non obvious limitations or issues involved?

Is it perhaps often not necessary since most code goes in banked flash anyway?

If so, is there any cost involved having it enabled but not used?

Anders J

[CrasyCat]

Hello

  If you want to use ROM_4000 memory area as well to store NON-BANKED section you need to make

  sure your application and run time library is build with option -OnB=b.

  See following comment extracted from  .prm file

 /* in case you want to use ROM_4000 here as well, make sure    that all files (incl. library files) are compiled with the    option: -OnB=b */

If you do not use that option you may get a linker error "Link error: L1907: Fixup overflow " while building the code.

See following thread for more info:

https://community.freescale.com/message/15820#15820

CrasyCat