PESL (Processor Expert System Library) is dedicated to power programmers, who are familiar with the microcontroller architecture - each bit and each register. PESL provides macros to access the peripherals directly. It should be used only in special cases when the low-level approach is necessary.
PESL is peripheral oriented and complements with Embedded Components, which are functionality oriented. While Embedded Components provide very high level of project portability by stable API and inheritance feature across different CPU/DSP/PPC architectures, PESL is more architecture dependent.
PESL commands grouped by the related peripheral can be found in Processor Expert Project Panel in PESL folder.