Datasheet PDF of 590 KB covering the tiny4, tiny5, tiny9 and tiny10, matching the Atmel AVR ATtiny4/5/9/10 family of very small 6-pin microcontrollers. These parts use the TPI programming interface rather than classic ISP, so the programming chapter is worth reading before connecting a programmer. The document should include pinouts, electrical characteristics and register descriptions. Technicians use it to identify the tiny SOT-23 style parts on a board, check pin roles and confirm supply voltage limits.
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.
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The standard format for schematics, block diagrams, power-sequence charts and service manuals.