Summary datasheet for the tiny2313, marked by the s suffix and a compact 166 KB PDF, corresponding to the Atmel AVR ATtiny2313. Summary editions typically contain the feature overview, pinout drawings, a register summary and ordering codes rather than full peripheral chapters. It serves well as a fast reference for identifying pins on a populated board or confirming a package variant. Electrical limits, timing tables and programming algorithms are normally only in the full datasheet, which should be consulted for deeper work.
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. 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.