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Using an MC9S12C64 in place of an MC9S12C32

Question asked by BOB PAEHR on Jan 9, 2017
Latest reply on Jan 13, 2017 by BOB PAEHR

One of the projects that I worked on several years ago used an MC9S12C32 device.  I remember that I was running into a memory issue where I was overrunning the available Flash memory (0xC000-0xFFFF) by just a little bit.  I got around the problem at the time by consolidating some of the routines that handled sending text to my LCD, and that worked OK at the time.

 

Now I'm faced with making new changes to that code, which will certainly put me over the 16K requirement.  I'm not sure if I should try using 16K Paged memory at 0x8000 to 0xBFFF in the C32 device, or try replacing the C32 device with a C64 device.

 

1) If I were to replace my C32 device with a C64 device, will CodeWarrior automatically use the extra memory bank at 0x4000-0x7FFF without me having to do anything with any special Page registers?  How does the compiler know which device is the target MCU? (Sorry, it's been awhile...)

 

2) Would it be just as easy (no involvement or special definitions by me) to stick with the C32 device and use the Paged memory at 0x8000-0xBFFF?  If this is more desirable, what do I have to do in my C-Code to let the CodeWarrior compiler use this Paged memory? (I would just want to use one extra 16K Page, not worry about Page-Switching that bank of memory).

 

Thanks in advance for your help.

Bob P

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