I'm stuck in code part of my project which is to build a count down timer using input from user through keypad and display over LED's. if Anyone could share his/her code, that would be really appreciated.

A countdown timer is a down counter that counts from a specified time to 00:00. It is used in many devices such as washing machine, televisions, microwave ovens, etc. This countdown timer has three states: the running state where it counts down, the pause state where it displays the paused time and the reset state to set the countdown. The countdown is displayed on a set of four seven segment displays using the 8051 microcontroller (AT89C51). A buzzer sounds when the countdown gets over.