The AVR MCU is an enhanced RISC (Reduced Instruction Set CPU) RISC instruction set high-speed 8-bit MCU developed by ATMEL in 1997. AVR's single-chip microcomputer can be widely used in computer external equipment, industrial real-time control, instrumentation, communication equipment, household appliances and other fields.
The main features of AVR
High reliability, strong function, high speed, low power consumption and low price have always been an important indicator to measure the performance of single-chip microcomputers. It is also a necessary condition for the single-chip computer to occupy the market and survive.
The early MCUs were mainly due to low process and design level, high power consumption and poor anti-interference performance. Therefore, a conservative solution was adopted: the higher frequency division factor was used to divide the clock, which made the instruction cycle long and the execution speed slow. Future CMOS microcontrollers have adopted measures such as increasing the clock frequency and reducing the division factor, but this state has not been completely changed (51 and 51 compatible). Although some RISCs have been introduced here, they still follow the practice of clock division.
The introduction of AVR microcontroller completely breaks the old design pattern, abolishes the machine cycle, abandons the complicated instruction computer (CISC) and pursues the instruction completeness; adopts the reduced instruction set, uses the word as the instruction length unit, and the content-rich operands The opcode is arranged in one word (this is the case for most single-cycle instructions in the instruction set). The instruction fetch cycle is short, and the instruction can be prefetched to realize the pipeline operation, so the instruction can be executed at high speed. Of course, this speed increase is backed by high reliability.
The hardware structure of AVR microcontroller adopts the compromise strategy of 8-bit machine and 16-bit machine, that is, the local register storage (32 register files) and the single high-speed input/output scheme (ie, input capture register, output compare match register and corresponding Control logic). The instruction execution speed (1Mips/MHz) is improved, the bottleneck phenomenon is overcome, the function is enhanced, and the overhead of peripheral management is reduced, the hardware structure is relatively simplified, and the cost is reduced. Therefore, AVR MCU has achieved an optimal balance in terms of software/hardware overhead, speed, performance and cost, and is a cost-effective single-chip microcomputer.
AVR microcontroller embedded high-quality Flash program memory, easy to erase, support ISP and IAP, easy to debug, develop, produce and update products. Built-in long-life EEProm saves critical data for long periods of time and avoids loss of power. The large-capacity RAM on the chip not only satisfies the general use, but also supports the use of high-level language development system programs and expands the external RAM like the MCS-51 microcontroller.
The I/O lines of the AVR MCU all have configurable pull-up resistors, which can be individually set to input/output, settable (initial) high-impedance input, and strong drive capability (can eliminate power-driven devices). The I/O port resources are flexible, powerful, and fully utilized.
The AVR microcontroller has a variety of independent clock dividers for URAT, I2C, and SPI. Among them, the prescaler with up to 10 bits combined with the 8/16-bit timer can be used to set the timing of various grades by software setting the division factor. The AVR microcontroller uniquely uses a timer/counter (single) bidirectional count to form a triangular wave, and then cooperates with the output compare match register to generate a design method with variable duty cycle, variable frequency, and phase-variable square wave (ie, pulse width). Modulation output PWM)" is even more refreshing.
Enhanced high-speed synchronous/asynchronous serial port with hardware generated check code, hardware detection and check debugging, two-stage receive buffer, automatic adjustment of baud rate (received), masked data frames, etc. Reliability, convenient programming, more convenient to form a distributed network and realize complex applications of multi-machine communication system, serial port function greatly exceeds the serial port of MCS-51/96 single-chip microcomputer, plus AVR single-chip high-speed, short service time is short, so it can achieve high Baud rate communication.
Byte-oriented high-speed hardware serial interface TWI, SPI. TWI is compatible with I2C interface, and has the functions of ACK signal hardware transmission and identification, address recognition, bus arbitration, etc. It can realize multi-machine communication of all four combinations of master/slave receiving/sending. The SPI supports multi-machine communication of four combinations of master/slave.
AVR microcontroller has automatic power-on reset circuit, independent watchdog circuit, low voltage detection circuit BOD, multiple reset sources (automatic power-on reset, external reset, watchdog reset, BOD reset), settable start delay Run the program to enhance the reliability of the embedded system.
AVR MCU has a variety of power-saving sleep modes, and can operate with wide voltage (5-2.7V), strong anti-interference ability, can reduce the software anti-interference design workload and hardware usage in general 8-bit machines.
AVR microcontroller technology embodies a variety of devices (including FLASH program memory, watchdog, EEPROM, synchronous/asynchronous serial port, TWI, SPI, A/D analog-to-digital converter, timer/counter, etc.) and various Features (enhanced reliability reset system, power-down anti-jamming sleep mode, multi-class interrupt system, timer/counter with diversified functions such as input capture and compare match output, I/O with replacement function Port ...) in one body, fully embodies the development direction of the single-chip technology from the "self-defense" to the "system-on-chip SoC". In summary, AVR MCUs are well-known and unique, and they are worthy of being the best among 8-bit machines.
Selection of AVR series single chip microcomputer
The AVR microcontroller series is complete and can be used in a variety of different occasions. AVR microcontroller has 3 grades:
Low-grade Tiny series AVR MCU: Mainly Tiny11/12/13/15/26/28;
Mid-range AT90S series AVR MCU: Mainly AT90S1200/2313/8515/8535, etc.; (Declining or transitioning to Mega)
High-end ATmega series AVR microcontrollers: Mainly ATmega8/16/32/64/128 (storage capacity is 8/16/32/64/128 KB) and ATmega8515/8535.
AVR device pins are available from pin 8 to pin 64 and are available in a variety of packages.
best e cig,e cig vaporizer,best e cig vape,e cigaratte,vape cigratte
Newmax Electronics Co.,Limited , https://www.advvape.com