eeprom

[devis]

I'm using a nmiy0020 board with forth switched off. I use an EEPROM (8k) in U4 to store my program. Is there a way to use the 68hc11 internal eeprom (B600-B7FF) for storing variables while using an 32k EEPROM (my program is getting too big...). The memory map shows they'd overlap... Is there a solution for this??
dbhappy with one, thanks
/devis

[nmitech]

Configs the jumper H5 for two-32K device setup.

[list=A]
If a 32K device installs on U4, You can use the internal eeprom for data storage and still have up to 18-Kbyte of contigous memory from 0xB800 - 0xFFFF. This is twice memories as large as your current program.
Or up to 30-Kbyte split memory from 0x8000 - 0xAFFF, 0xB800 - 0xFFFF.

Or U2 can be installed with 32K Sram for your variables or data storage and the ram can be battery-backed instead of using internal eeprom. In this case, if you turn off the internal eeprom, you only gain 512-byte more for your program memory. To get entire 32-Kbyte program, new PAL equations for the new memory map is required.

[/list=A]

[devis]

thanks for your help. if i understand you correct, one has to program the eeprom "starting @ 0xB800 to use 18Kb, and the internal EEPROM will still be accessible on the memory map, in spite of it being physically overlapped??

[nmitech]

You can always be able to access to the internal eeprom, 0xB600 - 0xB7FF regardless of the memory area being overlapped, the internal memories always have priority.

You can start your code anywhere from 0xB800-0xFFFF if your program less than 18-Kbyte. Or if your program larger than 18-Kbyte you can start your code from 0x8000 - 0xAFFF and remember to skip or jump your code over the overlap area, 0xB000 - 0xB7FF. Some of the compilers have the option to place the code in the split memories. If not, you must re-arrange your program to handle this.