hallo, I am currently working on AT89C51CC03, with using AT89STK-06 Board. I am using Flip 3.4.1, Keil uvision4 and Hyperterminal S/Ws. I have sample programs of atmel site. By mistake i was using AT89C51CC01 on AT89STK-06 Board and this work properly, but now i change this microcontroller with AT89C51CC03 then the Board not going in ISP mode, While in AT89C51CC01 work in ISP mode. After changing my microcontoller on Board i press Reset and ISP buttons simultaniously and leave first Reset then ISP, so the controller have in ISP mode. Then i select device AT89C51CC03 in Flip s/w and select RS232 as communication medium then it´s always give error like "Time out Error". I know that AT89STK-06 Board support this both AT89C51CC01 and AT89C51CC01. I try it 4-5 times, but this note working. May be my controller not going in ISP mode. or There is problem in Board. or other. Please give me ur advice and answer related to this problem. Thanks in advance.