Datasheet stored as a 1.05 MB PDF and named only doc6327, a document number with no component name in it. That style of numbering follows the literature codes Atmel gave its datasheets, so it most likely covers one of their microcontrollers or related parts, and the title page identifies the exact device. Use it for pin functions, electrical limits, memory organisation and programming details. Before relying on it, check the chip marking and package against the document, since closely related variants can differ in pinout and features.
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.