Datasheet for the Microchip PIC16CE62x family, 1.12 MB, covering OTP microcontrollers that integrate EEPROM data memory alongside comparators. The x in the name indicates several members with different program memory sizes. It gives pin assignments, oscillator options, comparator and voltage reference details and electrical limits. Because these are one-time programmable parts, a faulty chip normally has to be replaced with a programmed equivalent, so the document mainly helps with pin tracing, supply checks and confirming compatible substitutes.
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.