AVR family is quite new in integrated processor RISC family. These microcontrollers can solve many embedded problems. They differ from other integrated processor RISC families by high speed performance, and by big deficiency. Because of this AVR RISC processors can be used instead some other 16 bit processors.
In other hand AVR processors are easy to program. Letâ€™s see why AVR from Atmel are becoming so popular:
- Very fast Harvard architecture. Most instructions are held in one clock cycle. AVR can be clocked in up to 16MHz so this means about 16MIPS;
- Not a specific feature, but AVR have internal Flash which can be reprogrammed about 1000 times without failing. According to this processors can be programmed directly in circuit without removing them off. This speeds up development of embedded applications.
- Integrated Processor RISC AVR command system from beginning was developed to be effectively compiled using C language. This is why compiled code for AVR is very effective than in other microcontrollers. In this case you get better performance and smaller code size.
- There are 32 registers in AVR. And they all directly work with processing unit. This also decreases code size and increases program performance. In other microcontrollers there are special registers – accumulators, where you have to load you value. After commend is finished you have to move this value to other register and so on. So instead 3 commands AVR can do this in ONE.
- There are many cheap and convenient development environments for AVR like AVRStudio, Wavrasm, also there are various versions of programmers for this type of controllers. Even powerful C compiler you get for free â€“ AVR GCC;
- AVR RISC processors are rich in peripherals like PWM, UART, timers, Analog comparators, TWI, ISP, interrupt abilities;
- You donâ€™t have to bother about memory banks and switching between them because this architecture doesnâ€™t have them like in PIC;
- All AVR microcontrollers have EEPROM memory which can be reprogrammed more than 100000 times.
There are three families of Integrated Processor RISC AVR:
- Tiny AVR â€“ cheap small processors on 8 lead packages;
- Classic AVR â€“ base AVR line up to16 MIPS, 2 â€“ 8 Kbytes Flash, 128-512 Kbytes SRAM, 64-512 Kbytes EEPROM;
- Mega AVR â€“ most advanced of AVR family with up to 16 MIPS, up to 128 Kbytes Flash, up to 4Kbytes SRAM, 10 ADC channels, ADC, 8×8 multipliers.
AVR is my Integrated Processor RISC choice.