at mel presentation jd f 07

7/30/2019 At Mel Presentation Jd f 07

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ATMEL

AVR 8 bit RISC

MICROCONTROLLERS

a general comparison


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A little history

The PIC (Programmable Interrupt Controller) appearedaround 1980.

8 bit bus

executes 1 instruction in 4 clk cycles

Harvard architecture

AVR (1994)

8 bit bus

one instruction per cycle



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AVR 8-Bit RISC High Performance

True single cycle execution

single-clock-cycle-per-instructionexecution

PIC microcontrollers take 4 clockcycles per instruction

One MIPS (mega instructions per second) per MHz up to 20 MHz clock

32 general purpose registers

provide flexibility and performance when using highlevel languages

prevents access to RAM


separate bus for program and data memory


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AVR 8-Bit RISC Low Power

Consumption

1.8 to 5.5V operation

will use all the energy stored in

your batteries

A variety of sleep modes

AVR Flash microcontrollers have

up to six different sleep modes fast wake-up from sleep modes

Software controlled frequency


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AVR 8-Bit RISC Compatibility

AVR Flash microcontrollers share a

single core architecture

use the same code for all families

1 Kbytes to 256 Kbytes of code

8 to 100 pins

all devices haveInternal oscillators


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AVR 8-Bit RISC - picoPower

Technology

PicoPower enables AVR to achieve the

industrys lowest power consumption with 650

nA with a RTC (real time clock) running and

100nA in Power Down sleep (from ATMELwebsite)

- True 1.8V Supply Voltage

- Minimized Leakage Current

- Ultra Low Power 32 kHz Crystal Oscillator- Digital Input Disable Registers

- Power Reduction Register


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So what chip should I use?

the application chooses the chip

each family has a large number of variants

the number of pins, the package, the costof the chip, the peripherals, the operatingvoltage, the current consumption, and soforth

PIC is more application oriented AVR mostly pin #s and flash memory

differ


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Many choices

TI(MSP430), Zilog (Z8), Freescale (SC8),

Atmel(AVR), Microchip (PIC), ST,

Renesas / Hitachi (Mx or H8), Philips

(8051) as just few of the many possibleselections

MICROCHIP ATMEL and MSP430

FREE SAMPLES


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AVR has very good documentation

Wide use

AVRFreaks .net

Free software


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Most Importantly!!!

Best C compiler to start programming in C

and it is FREE

Code Vision AVR http://www.hpinfotech.ro/

AVR Studio 4 also free from:http://www.atmel.com/dyn/products/tools_card.asp?tool_id=2725


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Code Vision AVR setup

After opening Code Vision AVR

click on:

tools

codewizardAVR

select you chip version and

oscillator frequency


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Set/clear the pins you want


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LCD setup (LCD from

microprocessors lab)

Control LCD with port A:


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Setting up the Analog to Digital

conversion

8 bit A/D on channel 3

(PORTA.3)

at mel presentation jd f 07

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