Filed as SDLS167, this 375 KB PDF is a semiconductor datasheet whose name carries no part number, only a literature code of the kind Texas Instruments assigns to its logic family documents. The covered device and its variants are listed on the title page. Technicians use such sheets to identify pins, check expected input and output levels, and find a compatible substitute. Compare the package suffix and logic family on the actual chip with the ordering table before ordering a replacement.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @datasheet_technar_org. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.