Levels of abstraction

Processor Expert provides components with several levels of abstraction and configuration comfort.

• LDD components - Logical Device Drivers. The LDD components are efficient set of components that are ready to be used together with RTOS. They provide a unified hardware access across microcontrollers allowing to develop simpler and more portable RTOS drivers or bare board application. See Logical Device Drivers topic for details.
• High level components - Components that are the basic set of components designed carefully to provide functionality to most microcontrollers in market. An application built from these components can be easily ported to another microcontroller supported by the Processor Expert. This basic set contains for example components for simple I/O operations (BitIO, BitsIO, ByteIO, ...), timers (EventCounter, TimerInt, FreeCntr, TimerOut, PWM, PPG, Capture, WatchDog,...), communication (AsynchroSerial, SynchroMaster, SynchroSlave, AsynchroMaster, AsynchroSlave, IIC), ADC, internal memories.

  This group of components allows comfortable settings of a desired functionality such as time in ms or frequency in Hz without user knowing about the details of the hardware registers. microcontroller specific features are supported only as processor specific settings or methods and are not portable.

  The components inheriting or sharing a high-level component(s) to access hardware are also high-level components.

• Low level components - Components that are dependent on the peripheral structure to allow you to benefit from the non-standard features of a peripheral. The level of portability is decreased due to a different component interface and the component is usually implemented only for a microcontroller family offering the appropriate peripheral. However, you can easily set device features and use effective set of methods and events.
• Peripheral initialization components - Components that are on the lowest level of abstraction. An interface of such components is based on the set of peripheral control registers. These components cover all features of the peripherals and are designed for initialization of these peripherals. Usually contain only Init method, see Typical usage of peripheral initialization components topic for details. The rest of the function has to be implemented using a low level access to the peripheral. This kind of components are located at: processor Internal Peripherals/Peripheral Initialization Components of the components library and they are available only for some processor families. The interface of these components might be different for a different processor. The name of these components starts with the prefix 'Init_'.

  Table 1. Features of components at different level of abstraction

  Feature	LDD components	High level	Low level	Peripheral Init
  High-level settings portable between different microcontroller families	partially	yes	partially	no
  Portable method interface for all processor families	yes	yes	partially (usually direct access to control registers)	Init method only
  Processor specific peripheral features support	mostly yes	partially	mostly yes	full
  Low-level peripheral initialization settings	partially	no	partially	yes
  Speed mode independent timing	yes	yes	mostly yes	no
  Events support	yes	yes	yes	no (direct interrupt handling)
  Software emulation of a component function (if the specific hardware is not present)	no	yes	no	no
  Support for RTOS drivers creation	yes	no	no	no