digital lock

sir can u pls explain the working of Digital Lock Using AT89C2051 with LCD and Keypad - Assembly?

Project works on simple user inputs.

1. Controller ask user to enter unlock code
2. It then checks if entered code is 12345, if yes then it will take user to change unlock code.
3. if its not 12345 then entered code is compared with stored code. if it matches door is opened and controller waits for '#' key to be pressed so that door locks again.
4. if entered code matches neither to 12345 nor stored unlock code then error message is printed with number of tries left.
5. if three tries are over then controller blocks the user code and ask user to enter master password to open door.

Thats the flow of code.