1 Compatibility Checklist

The following items are common compatibility concerns and should be considered when evaluating migration between devices. Specific applications may also include additional related items.

  • Package and PCB footprint compatibility
  • Peripheral availability and number of instances
  • Voltage, current, and thermal requirements
  • Pinout functions and locations, including:
    • VDD and VSS power pins
    • MCLR
    • Buck regulator power pins
    • Oscillator pins if using a crystal or external clock source
    • Fixed-pin peripherals (I2C, JTAG, interrupts)
    • Analog functions
      • ADC core and channel assignments
      • Comparator inputs and DAC output
      • Constant current sources
      • Operational amplifiers (op amps)
  • Flash and RAM memory size constraints

Most peripherals allow their corresponding pin functions to be placed on any device pin using the Peripheral Pin Select (PPS) functionality. The Remappable Pin (PRn) index number may change for a given pin from one device to another. Application software may need to be modified for PRn assignments, pin direction settings (TRISx) or analog function configuration (ANSELx), depending on the device configuration.