Microcontroller families
The MC kernel refers to the set of specific instructions, the cyclic operation of the processor, the organization of both program and database memory, the interrupt system and a basic set of peripheral devices (PU).
Representatives of one family differ from each other by the size of program and database memory, as well as by the variety of PU.
Unite all the MCs in the family the same binary programming code.
The families are divided into:
MSC-51, made by Intel. Monocrystal MC based on Harvard architecture. The main representative of this family is the 80C51 which is based on CMOS technology. Although these controllers were developed back in the 1980’s, they are still widely used. And today many companies such as Siemens, Philips and others produce their controllers with similar architecture.
PIC (Microchip). Harvard architecture MC. It is based on the architecture with reduced instruction set, built-in command and data memory, low power consumption. This family includes more than 500 different MCUs (8-, 16-, 32-bit) with different periphery, memory and other characteristics.
AVR (Atmel). The high-speed controllers are designed on their own architecture. The basis of the controller is a Harvard RISC processor with independent access to program and database memory (Flash ROM). Each of the 32 general-purpose registers can operate as a register-accumulator and aggregate 16-bit instructions. The high performance of 1 MIPS per MHz clock frequency is enabled by an instruction ordering that executes one instruction while preparing for the next. To support its products Atmel provides a free and high-quality development environment Atmel
ARM (ARM Limited) are designed on their own architecture. The family includes 32-bit and 64-bit MCUs. ARM Limited only develops cores and their tools and sells production licenses to other companies. These processors consume little power, so they are widely used in the production of cell phones, game consoles, routers, etc. Companies that have purchased licenses include: STMicroelectronics, Samsung, Sony Ericsson, etc.
STM (STMicroelectronics). 8-bit controllers (STM8) belong to the category of high-reliability, low-power products. This family also includes controllers STM32F4 and STM Their basis is 32-bit Cortex. These controllers have a perfectly balanced architecture and have a great development perspective.
These are not all families of microcontrollers. Here we are just talking about the main ones.
Types of microcontroller packages
There are no external differences between the MCs and other microcontrollers. Crystals are placed in packages with a certain number of outputs. All MC’s are available in only 3 types of packages:
The DIP package has two rows of pins. The distance between them is 2.54 mm. The pins are inserted inside the holes on the contact pads.
The SOIC package. This is suitable for installations that require the pins to be resoldered to the pad. The pin spacing is 1.27 mm.
QFP (TQFP) packages. The pins are located on all sides. The distance between them is 3 times less than in DIP. The enclosure is square in shape. Intended for surface soldering only.
QFN housings. The smallest compared to the previous ones. The contacts come out 6 times more often than in DIP. The QFN is very popular in industrial production, as it allows to reduce the size of produced devices.
QFP package
Each of the packages has its own application points. The first 3 can be used by hobbyists.