>I guess there is some problem with your programmer,
>Can you be more specific and tell us what "It doesn’t work” means.
>Does your programmer recognize the chip(which programmer are you using)…

My programmer can work with both types of chips. And I'm sure that hex-file was written correctly.

>If its OK with the burning process, Tell us more about >your application circuit does it us an external memory ?

My application uses LCD, RS485 and I2C bus memory. It doesn't use external memory. It gets impulses from 2 devices, counts them, calculates and shows difference on LCD.