If any of the button is pressed in a row, it will take the corrosponding column to a low state which tells us that a key is pressed in that row. If button 1 of a row is pressed then Column 1 will become low, if button 2 then column2 and so on... Now lets move on to the programming part of keypad in our next section.
How to write a first program in Keil for 8051; In this topic we deal with the programming of 8051 microcontroller. And also learned how to write a program in Keil. For AT89C51 programming we used a Keil µVision software. Programming can be C, C++ or in any another language. Steps to use the Keil