This part is a kind of semiconductor called 74C922.

Function of this product has 16/ 20-Key Encoder.

Manufacturers : National Semiconductor

Image and pinout :

Some of the text within the PDF file :

MM54C922 MM74C922 16-Key Encoder MM54C923 MM74C923 20-Key Encoder July 1993 MM54C922 MM74C922 16-Key Encoder MM54C923 MM74C923 20-Key Encoder General Description These CMOS key encoders provide all the necessary logic to fully encode an array of SPST switches The keyboard scan can be implemented by either an external clock or external capacitor These encoders also have on-chip pullup devices which permit switches with up to 50 kX on resistance to be used No diodes in the switch array are needed to eliminate ghost switches The internal debounce circuit needs only a single external capacitor and can be defeated by omitting the capacitor A Data Available output goes to a high level when a valid keyboard entry has been made The Data Available output returns to a low level when the entered ke [ ... ]

74C922 PDF Datasheet Download