Microchip datasheet for the PIC18Fxx8 family, the largest file in this set at 7.43 MB, where xx marks the different memory and pin-count variants. These PIC18 devices include a CAN controller, and the document covers pinouts, CAN module registers, oscillator modes, peripherals and electrical characteristics. It is useful when servicing automotive or industrial boards, tracing CAN transmit and receive lines to the transceiver and locating ICSP pins. Read and back up the existing firmware before any reprogramming attempt.
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.