PDF datasheet, about 253 KB, for the KB9028Q, an ENE keyboard and embedded controller found on many notebook mainboards. It describes the pinout, supply pins and internal functions such as GPIO, ADC, PWM for fans, SMBus for battery communication and the SPI interface to the BIOS flash. A repair technician uses it to identify pins when measuring signals on a board that will not power up or charge. It is a generic component reference, so pair it with the board schematic to see how each pin is wired.
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 @ic_mosfet_pdf_datasheets. 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.