The need for this project aroused when once I was trying to interface uart and multiplexed ssds together. The problem was that I had to do 2 process simultaneously that is receive characters from uart send them back to uart, print them at the same time update all ssds. Now ssds use persistent of vision that is a particular ssd is turned on digit is displayed on it then after few microseconds other ssd is turned on and corresponding digit is displayed and this goes on for other ssds also. So as a solition to this, a mechanism had to be developed that after few us turns on a ssd displays digit, then after few us turns other ssd on displays corresponding digit and at the same time receive digits from uart put them back and displays on term. And apart from displaying on term also update digits to be displayed on ssds.