MSP430 DATA_SECTION to write in C segment issue

Hi C A,

If you don't use VARIABLE anywhere, it is likely being optimized out. You can resolve this by also using the RETAIN pragma to tell the compiler and linker not to remove it. So your code might now look like:

#pragma DATA_SECTION(VARIABLE, ".infoC")
#pragma RETAIN(VARIABLE)
const unsigned int VARIABLE = 0x1234;

Now when you look at your .map file you should see that VARIABLE was put in INFOC memory at address 0x1040.

There is more info on the RETAIN pragma in the compiler guide, www.ti.com/lit/pdf/slau132

Regards,

Katie

Hi C A,

C A said:

think I got an error only when the current values in the flash memory are different than the ones I declare in the pragma directive

By default, CCS only erases main memory when loading the program. You are trying to now write a value into INFO memory, so INFO memory needs to be erased before the write can occur. You can change this in CCS by going to Project > Properties > Debug > MSP430 Properties and scrolling down to where it has "Erase Options". By default it will be set to "Erase main memory only". You'll want to set it to "Erase main and information memory". With this setting, along with main flash it will also erase INFO B,C,D sections, but not erase the protected INFOA segment (which usually contains calibration data that you want to keep).

I suspect that if you try this setting, your error will go away, because the INFOC flash will be erased before programming.

Regards,

Katie