Grundlagen Microcontroller Introduction · Introduction – What is a microcontroller? ... Heat...
Transcript of Grundlagen Microcontroller Introduction · Introduction – What is a microcontroller? ... Heat...
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Günther GridlingBettina Weiss
Grundlagen MicrocontrollerIntroduction
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Lecture Overview● Introduction
– What is a microcontroller?
– difference between microcontroller and microprocessor
– reasons for existence of microcontrollers
– fields of application
– microcontroller types
– frequently used terms
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● A Simple Control Task: Heating– periodically read temperature (4 bit digital value)
– turn on/off heating according to temp. (1 control line)
– current temperature is displayed (display 8+3 bits)
– user can adjust temp. thresholds with buttons (4 btns)
– serial interface to download temp. data for last 24 h (2 bit)
● > 20 digital I/O lines, timer, serial interface
What is a Microcontroller?
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● Components we need:– CPU (Z80)
– 2x PIO (2x 16 = 32 digital I/O lines)
– SIO (serial I/O)
– CTC (timer)
– memory (SRAM, Flash, EEPROM)
● requires 8 chips (+ their connections) on PCB
Heat Control With Z80
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PCB: euro format 10x16 cm
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(Autorouter 81% finished)
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● If we do this with a microcontroller:require– CPU
– at least 20 digital I/O lines
– serial interface
– timer
– memory (SRAM, Flash, EEPROM)
Heat Control With ATmega16
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● Components we need: 1 microcontroller– All components are integrated into one single chip!
What is a Microcontroller?
PCB: less than quarter euro format 5x8 cm
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size reduction of more than factor 4!
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● microcontroller integrates several components:– CPU
– memory
– digital I/O lines
– analog I/O lines
– interrupt controller
– counter/timer
– serial interface(s)
What is a Microcontroller?
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● smaller board area● faster development● easier debugging and upgradability● low cost● low power consumption● high reliability
Why Microcontrollers?
microcontrollers save time & money!
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● telecommunication● automotive industry● aerospace industry● household appliances, home automation● factory automation● ...
Fields of Application
mostly high quantities (90 in car) > huge market!
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● Many different controllers from many different vendors(e.g. PIC, ATmega16, HC11, 8051)
● controller family:– same CPU
– different peripherals (number of I/Os, timers, ...)
– e.g.: Atmel AVR ATmega family
Types of Microcontrollers
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● controllers are (4), 8, 16, 32 bit● we concentrate on small 8bit controllers
– no MMU (memory management unit)
– no DMA (direct memory access)
– no Cache● clocking frequency about 1 25 MHz
Types of Microcontrollers
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● Microprocessor: a CPU (e.g. in a PC)
● Microcontroller: single chip computer, contains I/O lines to directly monitor and control environment
● Digital Signal Processor: designed for signal processing (fast multiplications), often hybrid
Some Technical Terms
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● Embedded System: the microcontroller is part of the system, has a dedicated function(microwave, mobile phone, ...)
● RealTime System: a system which has to react to events within a given time frame; if the reaction comes too late, the results may be disastrous(breakbywire in car)
Some Technical Terms
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● Microcontroller: CPU + peripherals on one chip
● Microcontroller can be used standalone● Motivation for Microcontrollers: time &
money● Microcontroller families● Important terms
Lecture Summary