A controller is used to control a process or aspects of the environment. One example of the application of the microcontroller is to monitor our homes. As the temperature rises the controller to open the window and vice versa. At the time, the controller is built from logic components as a whole, thus making it bulky and heavy. After it was used mikrokprosesor so into the overall controller PCB is quite small. Until now, we still see the controller which is controlled by a microprocessor usual (Zilog Z80, Intel 8088, Motorola 6809, etc.). The process of ongoing downsizing of components, all the components needed to build a controller that can be packaged in a single chip. Thus was born the single-chip computer (one chip microcomputer) or also called a microcontroller. To learn more about the microchip you can see at www.microchip.com.
Microcontroller is an IC with a very high density, in which all the parts necessary for a controller has been packed in one chip, usually consists of:
- CPU (Central Processing Unit)
- RAM (Random Access Memory)
- EEPROM / EPROM / PROM / ROM
- I / O, Serial and Parallel
- Interrupt Controller
On average microcontroller has bit manipulation instructions, access to I / O directly and easily, and interrupt the process fast and efficient. In other words, the microcontroller is “single chip solution” that drastically reduce component count and design costs (the price is relatively low).
Aside from being a home monitoring system as above, microcontrollers often found in household appliances (microwave ovens, TVs, stereo sets, etc.), computers and equipment, cars and so forth. In some uses could be found in more than one processor in it. The microcontroller typically used for equipment that does not necessarily require high processing speeds. Although there may be between us imagine for controlling a microwave oven using a Unix-based system, controlling the microwave oven can easily use the smallest microcontroller. On the other hand if we want to control the missile in order to chase the neighbor’s dog always barks middle of the night, we will need a processor with a higher speed. Special nature of the microcontroller is small in size, saving power and flexibility cause the microcontroller is suitable for use as the registrar / recorder of data in applications that do not require the presence of the operator.
- Von-Neuman architecure
The microcontroller is designed based on this architecture pick a data bus used for the “fetch” instruction and data. Program (instruction) and data stored in the main memory together. When the controller is put address on an address in the main memory, the first thing to do is take instructions to be carried out and then took the supporting data from the instruction page. This method slows microcontroller operation.
- Harvard Architecture
This architecture bus pick a separate data and instructions, allowing the executions were carried out simultaneously. Theoretically this allows faster execution but on the other hand require a more complex design.
Today almost all microcontroller is CISC microcontrollers (Complete Instruction Set Computer). Usually have more than 80 instructions. The advantage of this is their CISC instruction that works like a macro, allowing programmers to use a single instruction replaces several other simple instructions.
- RISC Currently the industry trend to use microprocessor design RISC (Reduced Instruction Set Computer). By using fewer number of instructions, allowing land on chip (silicon real-estate) is used to enhance the ability of the chip. The advantage of RISC is simplicity of design, smaller chips, a little pin count and very little power consumption.
Below is feature commonly owned by RISC Processor:
Harvard Architecture, which allows access to programs and data simultaneously.
Instruction Pipe lining increase execution speed.
Orthogonal instruction set to ease in programming, allowing each instruction to be operated at the register or used in some addressing mode, these instructions do not have a particular combination and also without exception.