topic Re: EEPROM Varible declarations in S12 / MagniV Microcontrollers

EEPROM Varible declarations

Kantha — Tue, 13 Feb 2007 17:30:32 GMT

Hi,

How to declare variable to the specific eeprom address and initialize to specific value at the same time

Regards,

Kantha

Re: EEPROM Varible declarations

Lundin — Tue, 13 Feb 2007 19:45:13 GMT

Assuming that you are using Codewarrior C compiler. Might be wise to post such info.

Make a read only segment in the .prm file at the address where you want the variable(s).

Then put your variables inside
#pragma CONST_SEG SEGMENT_NAME

And declare variables as global and constant. Set the init values as usual for constants in C.

Depending on MCU, there might be lots of other things to concider as well.
Might be wise to post which MCU you are using.

Re: EEPROM Varible declarations

Kantha — Tue, 13 Feb 2007 19:54:20 GMT

Hi,

I am using MC9S12DB128 and cosmic compiler

Regards,

Kantha

Re: EEPROM Varible declarations

Lundin — Tue, 13 Feb 2007 23:22:21 GMT

Ok, no idea in that case.

As a sidenote, make sure to setup INITEE if you wish to use the whole eeprom, since it is located at address 0 out of reset, and therefore half-way hidden behind the cpu registers in the memory map.

Re: EEPROM Varible declarations

Zeke — Wed, 14 Feb 2007 09:15:34 GMT

There are two ways may do this.

1.
a)declare a EEPROM point

@eeprom U8(or U16) *eeptr;

b)give a address to point

eeptr = (void*)0x880;

c)give point a value

*eeptr = 123;

2.
a) allocate a section at *.lkf file

+seg .eeprom -b0x0880 -m0x10 -n.eevalue

b) use #pragma

#pragma section @eeprom {eevalue}
@eeprom U8 EEmember1 = 0x80;
.....
.....
#pragma section {}

I hope these ways can help you.

Message Edited by Zeke on 2007-02-1401:33 AM