2.5 Significance of Peripheral Libraries (PLIBs) in MPLAB Harmony v3

This is the lowest level interface to the peripherals of a device. This is named as a library, but it consists of source (.c) and header (.h) files. Typically, each peripheral instance has a source and header file associated with it. The Application Program Interface (API) implementation is kept simple, such that the most of it will be direct peripheral register access.

Most API names and structures are consistent across devices which helps in driver portability. Typically, driver layers use PLIB API calls. Therefore, PLIBs are closely associated with peripherals, and these vary from device-to-device. Most PLIBs can be used either in polled mode or in interrupt mode. To realize polled mode, PLIBs have blocking calls. Interrupt mode supports ISR functionality with call-back support. There is no error checking, sanity checks, or state maintenance in a PLIB. The PLIB has clean code and no conditional macros (#if, #elif.) for readability.