PDF datasheet, 255 KB, labelled SDLS177 with no device description in the name. Texas Instruments documents many standard logic ICs under SDLS literature codes, so check the heading to learn which part and package variants are covered. Contents typically include a logic diagram, pinout, truth table and DC characteristics. When a board shows a missing or stuck digital signal, these details let you test the chip in circuit, confirm its supply pins, and verify a substitute before soldering it in.
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.