PDF datasheet covering the NXP LPC1768, LPC1766, LPC1765 and LPC1764 ARM Cortex-M3 microcontrollers, about 313 KB in size. Expect pin functions, package outlines, absolute maximum ratings and a feature overview of the members listed in the name. It is handy when tracing power and clock pins on an embedded board, checking the JTAG or SWD lines before reprogramming, or confirming whether a replacement part is pin compatible. The suffix and package printed on the chip should match the variant you look up, since flash and RAM sizes differ.
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.