Arbitrary Waveform Simulation using microcontrollers and Real time clock

Hi I am doing a project on Arbitrary Waveform Simulation (any user defined waveform can be generated which is not possible in common signal generators)
using Microcontrollers Atmel Ic's AT89c51 and AT89S8252, Real Time clock (DS 1307), DAC (0800)
My project is almost in finishing stage.
I would like to know the program Digital Clock with alarm using DS1307 in simple steps like a flowchart.
Can anyone help me plz, itz urgent..

Thanks a lot!