thanks for your warning. I solve this problem change the mode 16789 to 396. yes you are right. it isnt necessarry to use portb.2 if I only write on the lcd . but it isnt my original program. it is a test. (can I use serial comminication) and get code for copy+paste from my previous program . also you are right about ossicilator. Iwill remove internal command. thanks all for I get your time and sorry for my bad english