topic Re: Init Value EEprom in S12 / MagniV Microcontrollers

Init Value EEprom

CCandido — Wed, 17 May 2006 08:13:18 GMT

Hi,

to initiate the EEPROM with some values, I use the DP256.

Tab_EEp = {00,08,...............}

Edited by Carlos Candido from Brasil.

Re: Init Value EEprom

Technoman64 — Thu, 18 May 2006 20:41:31 GMT

First thing you need to define the EEPROM segment in the prm file so the linker knows the location of the EEPROM in the memory map

/* Add this in the prm file above the RAM section */

EEPROM = READ_ONLY 0x0C00 TO 0x0FFF;

/* Add this to the prm file after the DEFAULT_RAM section *\

EEPROMDATA INTO EEPROM;

Now on to declaring the array in c code

/* We first need to tell the compiler which segment we want to use */

#pragma CONST_SEG EEPROMDATA

/* Now declare an array in the EEPROM segment with initialized values */

const int MyIntegerArray[5] = {1,2,3,4,5};

/* Return to default constant segment */

#pragma CONST_SEG DEFAULT

You can now declare this as extern const data in an include file so the array can be used by other code.

Message Edited by Technoman64 on 05-18-200608:43 AM

Re: Init Value EEprom

CCandido — Thu, 18 May 2006 23:34:13 GMT

Not, programing........

prm

EEPROM = READ_ONLY 0x0400 TO 0x0FFF;

DEFAULT_RAM INTO RAM;
EEPROMDATA INTO EEPROM;

--------------

in my code main.

#pragma CONST_SEG EEPROMDATA
const int MyIntegerArray[6] = {0,1,2,3,4,5};
#pragma CONST_SEG DEFAULT

-------------------------

progammer Staus:

Block Module Name      Address Range   Status
  0 EEPROM             400 -   FFF   Enabled/Blank/Unprotected - Selected <<<<<?
  1 FLASH_4000        4000 - 7FFF   Enabled/Blank/Unprotected - Selected
  2 FLASH_C000        C000 - FFFF   Enabled/Programmed/Unprotected - Selected
  3 FLASH_3         308000 -33BFFF   Enabled/Blank/Unprotected - Selected
  4 FLASH_2         348000 -37BFFF   Enabled/Blank/Unprotected - Selected
  5 FLASH_1         388000 -3BBFFF   Enabled/Blank/Unprotected - Selected
  6 FLASH_0         3C8000 -3FBFFF   Enabled/Programmed/Unprotected - Selected

congratulation........t+

Re: Init Value EEprom

Technoman64 — Thu, 18 May 2006 23:39:55 GMT

You must referance the Array some where in your code or the compiler will optimize the array out because it is never used.

Try in the main() function,

int Test;

Test = MyIntArray[0];

Re: Init Value EEprom

imajeff — Fri, 19 May 2006 04:16:00 GMT

wouldn't it also stick if marked static or something like that?

Re: Init Value EEprom

CCandido — Fri, 19 May 2006 04:52:05 GMT

test in debug_only OK,

$0400 = 00 01,00,02,..........00,05 ok,

programing........

Block Module Name Address Range Status
0 EEPROM 400 - FFF Enabled/Blank/Unprotected - Selected !!(not)

  1 FLASH_4000        4000 - 7FFF   Enabled/Blank/Unprotected - Selected
  2 FLASH_C000        C000 - FFFF   Enabled/Programmed/Unprotected - Selected
  3 FLASH_3         308000 -33BFFF   Enabled/Blank/Unprotected - Selected
  4 FLASH_2         348000 -37BFFF   Enabled/Blank/Unprotected - Selected
  5 FLASH_1         388000 -3BBFFF   Enabled/Blank/Unprotected - Selected
  6 FLASH_0         3C8000 -3FBFFF   Enabled/Programmed/Unprotected - Selected

not, programmer EEprom !!

status eeprom = Blank

Re: Init Value EEprom

imajeff — Fri, 19 May 2006 05:57:04 GMT

I don't think global vars should be optimized out.
I'm wondering if the utility can handle programming both EEPROM and Flash at the same time. I used GCC to test this global:

const int __attribute__((section(".eeprom"))) MyIntegerArray[6] = {0,1,2,3,4,5};

It looks good in the ELF output from GCC, but the S19 can't hold both memory regions because it outputs linear Flash addresses (i.e. 0xc0000 is start of PPAGE 0x30). Thing is, it should be able to work if the S19 is generated in banked format (i.e. 0x000400 eeprom and 0x308000 flash) like it probably does in CW.

Re: Init Value EEprom

Technoman64 — Fri, 19 May 2006 19:07:14 GMT

I have done this more than once with Codewarrior and a HCS12DJ256. The EEPROM is erased and programmed with no issues on my system.

Try moving the Test int out of the main() function and into global address. Also look at the Map file to determine if the compiler optimized the array out.

Re: Init Value EEprom

Lundin — Fri, 19 May 2006 19:43:24 GMT

A better way to do this in Codewarrior is at the bottom of the prm file:

ENTRIES

myVariable

END

And then somewhere in the program

const int myVariable = 123;

Though you can only do this with global const variables, I don't think it works with static since they are limited to the file they are placed in.

I'm not sure if I would trust
int Test;
Test = MyIntArray[0];

You never know what crazy things the optimizer might do with that. Maybe it will detect that Test is never used and remove it from the program. I suppose you could do something like

Type includeVar(Type t)
{
return t;
}

main()
{
(void) includeVar(myVariable);
}

But I think it is better to include it in ENTRIES as I mentioned first.