PIC18f2455 blink

[iugmoh]

Another question , I made a project on PIC16f877a but there isn't sufficient memory space to add additional code, so I change to PIC18F452 and make compile and it's compiled without any errors , IF I programm my chip and try practically Is't working ?

[skimask]

Another question , I made a project on PIC16f877a but there isn't sufficient memory space to add additional code, so I change to PIC18F452 and make compile and it's compiled without any errors , IF I programm my chip and try practically Is't working ?

The 16F877A and 18F452 have different registers, different options, different modules, different things that need to be configured before use.
Something made for one probably isn't going to port DIRECTLY over to another PIC without a few register changes, configuration changes, from here to there.
Check the datasheets for the differences.
And if it works on the '877, go thru the code. There are ways of optimizing memory use on the '877 (both the program and ram space) to get things to fit.
Are you out of program space or ram space?

[iugmoh]

program space is out

[skimask]

program space is out

Well, same thing applies. There's a lot of different ways of optimizing code...but, without seeing any of it, can't say what will work for you.

[iugmoh]

whats wrong in this code

for i=0 to 15
eeprom i,[0]
next i

[skimask]

whats wrong in this code

for i=0 to 15
eeprom i,[0]
next i

Read the manual, last paragraph of the explanation for EEPROM.

[iugmoh]

Oky, What is the different between EEPROM and DATA ?