Advantages of AVR over 51 series microcontrollers

      In 1997, Mr. A and Mr. V from ATMEL's Norwegian Design Center used ATMEL's new Flash technology to jointly develop a high-speed 8-bit microcontroller with a RISC reduced instruction set, referred to as AVR.

      Advantages and features of AVR microcontrollers

      Single-chip microcomputers have been widely used in military, industrial, household appliances, smart toys, portable smart instruments and robot manufacturing, which greatly improves product functions, precision and quality, and has simple circuits, low failure rate, high reliability and low cost. There are many types of single-chip microcomputers. Why do we choose AVR single-chip microcomputers in simple robot manufacturing and innovation?

       1. Easy to learn, low cost
      First of all, for non-professionals, the main reason for choosing AVR microcontrollers is that the threshold for entering AVR microcontroller development is very low. As long as you can operate a computer, you can learn the development of AVR microcontrollers. Microcontroller beginners only need an ISP download line to write the edited and debugged software program directly into the AVR microcontroller online, that is, they can develop various packaged devices in the AVR microcontroller series. Therefore, AVR microcontrollers are known as "one-line conquering the world" in the industry.
      Secondly, AVR microcontrollers are easy to upgrade. AVR program writing is to modify and burn the program directly on the circuit board, which is convenient for product upgrades.
       Thirdly, AVR microcontrollers are low-cost. To learn AVR microcontrollers, you can use the ISP online download programming method (that is, write the compiled program on the PC into the program memory of the microcontroller). You don't need to buy emulators, programmers, erasers, chip adapters, etc., and you can develop and apply all AVR microcontrollers, which can save a lot of development costs. The program memory can be erased and written more than 10,000 times without generating any scrapped products.

     2. High speed, low power consumption, and confidentiality
     First, the AVR microcontroller is a high-speed embedded microcontroller:
     1. The AVR microcontroller has the function of pre-fetching instructions, that is, when executing an instruction, the next instruction is taken in advance, so that the instruction can be executed within one clock cycle.
     2. Multi-accumulator type, fast data processing speed. The AVR microcontroller has 32 general working registers, which is equivalent to 32 overpasses for fast passage.
     3. Fast interrupt response speed. The AVR microcontroller has multiple fixed interrupt vector entry addresses, which can respond to interrupts quickly.
     Secondly, the AVR microcontroller has low energy consumption. For typical power consumption, it is 100nA when the WDT is turned off, which is more suitable for battery-powered application equipment. Some devices can work at a minimum of 1.8 V.
     Thirdly, the AVR microcontroller has good confidentiality performance. It has an unbreakable bit encryption lock Lock Bit technology, and the confidentiality bit unit is hidden deep inside the chip and cannot be seen with an electron microscope.

      3. The I/O port has strong functions and has A/D conversion circuits

      1. The I/O port of the AVR microcontroller is a real I/O port, which can correctly reflect the real situation of the I/O port input/output. It is an industrial-grade product with a large current (sink current) of 10-40 mA, which can directly drive the thyristor SSR or relay, saving peripheral driver devices.
     2. The AVR microcontroller has an analog comparator inside, and the I/O port can be used for A/D conversion, which can form a cheap A/D converter. Devices such as ATmega48/8/16 have 8-channel 10-bit A/D.
      3. Some AVR microcontrollers can form a zero peripheral component microcontroller system, so that this type of microcontroller can work without external components, which is simple, convenient and low-cost.
      4. The AVR microcontroller can reset the startup reset to improve the reliability of the microcontroller. There is a watchdog timer for safety protection, which can prevent the program from going out of control (flying) and improve the product's anti-interference ability.

       4. Powerful timer/counter and communication interface
       The timer/counter T/C has 8-bit and 16-bit, which can be used as a comparator. The counter external interrupt and PWM (can also be used as D/A) are used to control the output. Some models of AVR microcontrollers have 3 to 4 PWMs, which are ideal devices for stepless speed regulation of motors.

       The AVR microcontroller has a serial asynchronous communication UART interface, which does not occupy the timer and SPI synchronous transmission function. Due to its high-speed characteristics, it can work at a general standard integer frequency, and the baud rate can reach 576K.

Related questions and answers:

1) Why choose AVR microcontroller? Flash program memory can be erased and written more than 1,000 times, and no scrapped products will be produced. Some PICs
are OTP and can only be burned once. AVR program memory data is organized as 16 bits, and can also be understood as 8 bits. PIC is a 12/14-bit program
memory, which brings inconvenience to register transfer and arithmetic and logical operations.
(2) Why choose AVR microcontroller? High speed (50ns), low power consumption! The hardware uses Harward structure and has a pre-fetch instruction function,
so that instructions can be executed within one clock cycle. PIC takes 4 clock cycles to execute an instruction. MSC-51 takes 12 clock cycles
to execute an instruction.
(3) Why choose AVR microcontroller? Super-function and streamlined instructions! It has 32 general working registers (equivalent to 32 accumulators in 8051
, overcoming the bottleneck phenomenon caused by single accumulator data processing), 128B~4KB SRAM, and can flexibly use instruction operations.
(4) Why choose AVR microcontroller? Industrial-grade product! It has a large current (sink current) of 10-20mA or 40mA (single output), which can directly
drive SSR or relay; it has a watchdog timer (WDT) for safety protection, preventing program runaway and improving the product's anti-interference ability.
(5) Why choose AVR microcontroller? Program writing can be written in parallel (using a universal programmer) or erased and written using a serial online ISP
. In other words, there is no need to remove the IC and burn it on a universal programmer, but to modify and burn the program directly on the circuit board
, making it convenient for product on-site upgrades. It has ISP, JTAG and self-editing functions, which is the future development direction of microcontroller programming.
(6) Why choose AVR microcontroller? The I/O port of AVR is a real I/O port, which can correctly reflect the real situation of the I/O port. I/O port
It has input/output, tri-state high-impedance input, and can also set the internal pull-up resistor as the input terminal function, which is convenient for various application characteristics
(multi-function I/O port)
(7) Why choose AVR microcontroller? High confidentiality (LOCK)!
– Unbreakable Lock bit technology
– Unlike Mask ROM, which can be cracked by electron microscope – Flash unit is hidden deep inside the chip
– Flash that can be burned multiple times and has multiple password protection lock (LOCK) functions, so the product can be commercialized quickly, and
the program can be changed multiple times (product upgrade) without wasting IC or circuit board, greatly improving product quality and competitiveness.
(8) Why choose AVR microcontroller? AVR has an analog comparator inside, and the I/O port can be used for A/D conversion, which can form a cheap A/D converter
.
(9) Why choose AVR microcontroller? It can be reset to start reset. The AVR series has an internal power switch to start the counter, and the low level reset
(/RESET) can be directly connected to the Vcc terminal. When the power is turned on, the internal RC watchdog timer can delay the MCU from starting to execute the program
. This delay allows the I/O port to stabilize before executing the program, thereby improving the reliability of the microcontroller. Some also have an internal reset voltage detection circuit
BOD, and the detection voltage is adjustable.
(10) Why choose an AVR microcontroller? It has a power saving function (POWER DOWN) and an idle (IDLE) low power consumption function. The general power consumption
is 1 to 2.5 mA, and the typical power consumption is 100 nA when the WDT is turned off.
(11) Why choose an AVR microcontroller? Like the 8051, it has multiple fixed interrupt vector entry addresses and can respond to interrupts quickly. However,
the PIC has only one interrupt entry, and it must be queried before responding to the interrupt, which loses the best response interrupt time.
(12) Why choose AVR microcontroller? Some AVR devices such as AT90S1200/2343/ATtiny15 have an internal RC oscillator with
an operating frequency of -1MHz, which makes this type of microcontroller work without external components. It is a single chip, which is simple and convenient, and is
even better for use as an encryption device.
(13) Why choose AVR microcontroller? Counter/timer, C/T has 8 bits and 16 bits, which can be used as a comparator; counter external interrupt and
PWM (can also be used as D/A) are used to control output, and some have 3-4 PWMs, which are ideal devices for stepless motor speed regulation.
(14) Why choose AVR microcontroller? It has a serial asynchronous communication UART interface, which does not occupy the timer and SPI transmission function. Because of its high speed, it
can work at a general standard integer frequency, and the baud rate can
reach 576K. (15) Why choose AVR microcontroller? AT90S4414/AT90S8515 has an expandable external data memory of up to 64KB. Their
pin arrangement and functions are similar to those of 8051, and they can replace the application system of 8051 series microcontrollers (8751 or 8752). The only difference is the reset
level, which requires only swapping the reset resistor and capacitor positions. Many new functions are also added, such as WDT, A/D, PWM, etc.
(16) Why choose AVR microcontrollers? The operating voltage range is wide (2.7~6.0V) and the power supply has strong anti-interference ability. AT90LXX is a low-voltage
device (2.7~6.0V), AT90SXX voltage is (4.0~6.0V), and the lowest device ATtiny12 has reached 1.8V~5.5V.
(17) Why choose AVR microcontroller? AT90S4434/8535 has 8-channel 10-bit A/D; AT90S2333/4433 has 6-channel 10-bit
A/D; ATmega103/128 with more powerful functions has Flash 128KB, EEPROM 4KB, RAM 4KB, 48 I/O ports, 16 interrupt sources
, 8 external interrupts, SPI, UART, 8-channel 10-bit A/D, ISP.
(18) Why choose AVR microcontroller? It also has a large capacity EEPROM that can be erased and written 100,000 times, which is
convenient for data storage after power failure. It can remember the working state when power is off after power is on. EEPROM (64B~4KB).