Friday, May 21, 2010

CRC calculation part1

after studying the basic of CRC calculation,my supervisor give me a task. This task is so call reverse engineering by my supervisor. he give me 2 .txt file, inside the both .txt file got a set of string contain of hex value for exp:

FF FF OO FF FF FF A5 E1
FF FF O1 FF FF FF A5 E1
FF FF O2 FF FF FF A5 E1

From both of the .txt file my supervisor given me, i thought my supervisor will ask me to count the CRC value. But my thought is totally wrong, because he give me together with CRC value from both file and ask me to do a reverse engineering process to find out the process of counting the CRC value.

This is totally different from what I have learn from internet before. The most challenging part is to decided the devisor value. This is hard, because the both .txt file is so long. If i doing a one time long division with the 2 .txt file, it will take me around 2 days to completed the computation. I will use around 100 page of A4 paper to compute this long division.OMG....

If i doing a mistake during the computation process, then i will get the wrong result and wasting my time...haha