Can we use address space 0x8000 to 0xBFFF in MC9S08DZ96 as normal flash (not in paging mode)?

[ManojM]

Hi,
We are using the MC9S08DZ96 in one of our design. We have compiled the code and used the non-banked memory (which is PPAGE0+ PPAGE1+PPAGE3 as per datasheet fig 4.4) as normal flash and we almost fully utilized the non-banked flash.
Now we want to integrate the other module code in to this code for which we will require more flash, but we don't want to modify the code for accessing the extended flash through paging.

Can we use address space 0x08000 to 0x0BFFF as normal flash, instead of using it as extended flash (Basically we want to use this section of address space as per MC9S08DZ60, which does not support extended memory)?

[tonyp]

Sure you can.  Just don't mess with the PPAGE register.  You can always access the remaining Flash (for data only) through the LAP (linear address pointer).

[ManojM]

Good to know that it can be used as normal flash (not in paging mode). I would like to use it as program memory (not as data memory). Hope this should work as program memory without modification in source code, such as without using keyword "far" for functions residing in memory space (0x8000 to 0xBFFF) and without any PRAGMA definitions for functions and data in this memory space. Please confirm.

Thanks for your timely feedback.

[tonyp · Accepted solution]

Yes, you can use $8000-$BFFF for non-paged program code (provided you don't ever change the PPAGE register).

What I meant was the remaining memory (beyond the first 64K) is what you can now use for data only, accesible through the LAP.

[ManojM]

Thank you. It helps me lot.