AN 2594 - cant read data back ...

[finnb2]

Posted on July 14, 2010 at 10:36

AN 2594 - cant read data back ...

[domen23]

Posted on May 17, 2011 at 13:58

You sure you are doing not just checking the return value, but called EE_ReadVariable with the correct pointer?

You didn't include any code, that's why the questions might be silly :p

[finnb2]

Posted on May 17, 2011 at 13:58 Hey, this is what i do ... uint16_t VarValue = 0; uint16_t data[600]; void EE(int argc, char *argv[]) {       int n=0;       argc=argc;       if (0 == strcmp(argv[1], ''u''))       {           FLASH_Unlock();       }       if (0 == strcmp(argv[1], ''i''))       {           n = EE_Init();           printf(''\nInit = %d\n'',n) ;       }       if (0 == strcmp(argv[1], ''w''))       {           for (VarValue = 0; VarValue < 50; VarValue++)           {             n = EE_WriteVariable(VirtAddVarTab[1], 100-VarValue);             printf(''\nWr = %d\n'',n) ;           }            }       if (0 == strcmp(argv[1], ''r''))       {           n=EE_ReadVariable(VirtAddVarTab[1], data);           printf(''\nRd = %d\n'',n) ;           for (VarValue = 0; VarValue < 50; VarValue++)           {              printf(''%d -'',data[VarValue] ) ;           }            } }   ---   the array data[] contains zeros when i call the last paragraph..... reg Finn

[cnurton]

Posted on May 17, 2011 at 13:58

EEprom emulation, described in AN 2594 works OK. I have had it working on an STM32F100 micro. Here are a few things I have spotted from your code:

1.

Ensure you call the following in the correct order:

FLASH_Unlock();

EE_Init();

EE_WriteVariable

2.  You are not incrementing the address pointer of the array that you send to EE_ReadVariable, also when you call it only one int is returned. Then you try and print an array that has not been populated Try passing a pointer of a 16 bit int then load that into your array and call EE_ReadVariable in your for loop.

    if (0 == strcmp(argv[1], ''r''))

     {           n=EE_ReadVariable(VirtAddVarTab[1], data);           printf(''\nRd = %d\n'',n) ;           for (VarValue = 0; VarValue < 50; VarValue++)           {              printf(''%d -'',data[VarValue] ) ;           }            }

3.

VirtAddVarTab[1] is just one virtual address so every time you call EE_WriteVariable with VirtAddVarTab[1] you are updating different flash locations with the same virtual address.

        e.g.         1 = 100

                        1 = 99

                        1 = 98

                        1 = 97….. and so on

 Then when you call EE_ReadVariable you will return the last VirtAddVarTab[1] updated in flash.

So you may want to increment the virtual address pointer. Hope this helps!