SDLS213 is the only identifier on this 252 KB PDF datasheet, and it names no part directly. The prefix matches the style of Texas Instruments logic literature, so the document most likely covers a logic IC, though the exact device must be read from the title page. Technicians use such sheets to confirm pin numbering, truth tables and timing when probing a suspect chip with a scope or meter. Compare the family suffix and package type on the actual chip with the variants listed inside.
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.
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The standard format for schematics, block diagrams, power-sequence charts and service manuals.