//----------------------------------------------------------------------------
//Eeprom support module
//----------------------------------------------------------------------------
#include <Main.h>
#include <Eeprom.h>
//------------------------------ Constants: ----------------------------------
#define RBUFF 100 //EEPROM ring buffer size
#define RSIG 0xDA //record header signature value
//------------------------------ Variables: ----------------------------------
typedef struct
{
char Sig; //record header signature
int Val; //stored value
} EVal;
__no_init __eeprom EVal EVals[RBUFF]; //EEPROM ring buffer
static char EePnt = 0; //pointer to currently used record
//-------------------------- Read V from EEPROM: -----------------------------
int Eeprom_ReadV(void)
{
EePnt = RBUFF; //set incorrect pointer value
for(char i = 0; i < RBUFF; i++) //search signature in ring buffer
if(EVals[i].Sig == RSIG) //if signature found
{
EePnt = i; //initialize pointer
break;
}
if(EePnt == RBUFF) //if pointer incorrect (signature not found)
{
EePnt = 0; //set pointer to first array record
return(0); //return V = 0
}
return(EVals[EePnt].Val); //read V
}
//--------------------------- Write V to EEPROM: -----------------------------
void Eeprom_WriteV(int v)
{
char NewPnt = EePnt; //save previous pointer value
if(NewPnt++ == RBUFF) //advance pointer
NewPnt = 0; //roll-up pointer
EVals[NewPnt].Val = v; //save V
EVals[NewPnt].Sig = RSIG; //save signature at new location
EVals[EePnt].Sig = 0xFF; //clear signature at old location
EePnt = NewPnt; //save new pointer value
}
//----------------------------------------------------------------------------