First of all, Terribly sorry for double posting, but I accidentally posted my thread on the wrong forum.

Now, for the issue at hand, I am having problems reading the EEPROM in my project.

I am using an Atmel 89c5131 MCU with a built in 1K EERPM/RAM both Addressed between 0x0000 and 0x03FF (with a bit in the EECON SFR to distinguish them). however whenever I call the read function the program seems to freeze.

I read the Datasheet, and it said this:



so based on it, I made these 3 subroutines:

void EEPROM_Normal()
{
EECON=0x00;	//Allow usage of EPROM
AUXR=0x0C;	//Restore normal R/W Cycles						  
}

void EEPROM_Write()
{
EECON=0x54;	//Programming
EECON=0xA4;	//Sequence
Delay(5);		//Delay to give the EEBUSY time to rise
while((EECON==0xA5)|(EECON==0x01));		//Wait till EEBUSY is off					 
EEPROM_Normal();	//Restore normal situation
}

void EEPROM_Read()
{
EECON=0x02;	//Access EPROM
AUXR=0x2C;	//Extend the Read cycles to accomidate for slow memory
}

 

with EEPROM_Read() being called right before actions regarding Reading For example:

unsigned char xdata test[10] _at_ 0x000

void main()
{
unsigned char data[10],i;
EEPROM_Read();
for(i=0;i<10;i++)
data[i]=test[i];
EEPROM_Normal();
}
 

EEPROM_Write() being called right after modifying a variable, for example:

unsigned char xdata test[10] _at_ 0x000

void main()
{
unsigned char data={0,1,2,3,4,5,6,7,8,9},i;
EEPROM_Normal();
for(i=0;i<10;i++)
test[i]=data[i];
EEPROM_Write();
}

 

and EEPROM_Normal() after any reading session(and at the end of the writing routine) and resets the AUXR SFR for normal real cycles.

what am I doing wrong?

Heres a copy of the Datasheet:

http://www.datasheetcatalog.org/datasheet...oc4136.pdf

the pages relating to EEPROM are between 40 and 42, and include the EECON SFR.

Other possibly noteworthy information:

my Program is written on a 32K FLASH memory which is sitting also externally and addressed between 0x0000 and 0x7FFF (So its overlapping with EEPROM) though I'm guessing the PSENALE is suppose to prevent data and code mixups.

this is my first MCU project, so I may have made a newbie mistake... Dont overlook the obvious stuff :)

Later edit:

I am pretty sure the fault is in the EECON SFR, because when I made a software that just toggles EEPROM on and off while displaying "checkpoint" message on the LCD.

	lcd_display("Starting",0,0); //Start Checkark
	EPROM_Normal();
	lcd_display("EEPROM ON",0,0); //Enable EEPROM Checkmark
	EPROM_Shutdown();
	lcd_display("EEPROM OFF",1,0); //Disable EEPROM Checkmark, display on line 2

 

only the Starting and EEPROM OFF messages were displayed, the EEPROM ON was completely. the only think that seem to happen was a delay between the "Starting" and "EEPROM OFF" messages (~around 3 seconds delay)

heres the EPROM functions for refrence:

void EPROM_Normal()
{
EECON=0x02;	//Allow usage of EPROM
//AUXR=0x0C;	//Restore normal R/W Cycles						  
}

void EPROM_Shutdown()
{
EECON=0x00;	//Allow usage of EPROM
//AUXR=0x0C;	//Restore normal R/W Cycles						  
}
 

as you see, I commented out the AUXR to rule him out, leaving just EECON as problem source.

can someone please help me out this I really need to finish this project by Wednesday.

heres the image of the EECON SFR:



and heres the AUXR SFR: