Embedded systems 101 final
- 1. Embedded systems-101 BY Khaled el madawi K_madawi@yahoo.com
- 2. What is Embedded systems
- 3. 1.0 Embedded Systems • All systems that contain one or more processor to do specific functionalities and give responses upon receiving inputs. • This processor is not for general purposes like general purpose Processor in PC’s and notebooks.
- 4. 1.0 Embedded Systems(cont’d) Another definition: • Computing systems with tightly coupled hardware and software integration, that are designed to perform a dedicated function(s). • The word embedded reflects the fact that these systems are usually an integral part of a larger system, known as the Embedding System. Multiple embedded systems can coexist in an embedding system.
- 5. 1.1 Embedded Systems Applications • Quadcopters
- 6. 1.1 Embedded Systems Applications(cont’d) • Rovers
- 7. 1.1 Embedded Systems Applications(cont’d) • Engine control
- 8. 1.1 Embedded Systems Applications(cont’d) • Embedded communication
- 9. 1.1 Embedded Systems Applications(cont’d) • Fixed wing UAVs
- 10. 1.1 Embedded Systems Applications(cont’d) • Rockets
- 11. 1.1 Embedded Systems Applications(cont’d) • Satellites
- 12. 1.2 How Could these systems act like that? we have two paths Feed back systems: • Getting a feed back that gives for me a reading of a state that the robot is in it right NOW. • Pros: The most used, cause it’s reliability is very high. • Cons: Need observation to solve the uncertainty problem. Mathematical model: • Make a mathematical model for the Robot/system and predict the output from the input equation. (Y=A*X whereY is the output, A is the mathematical model of the system, and X is the input.) • Pros: It is the most way used when we can’t take a feedback from the system. • Cons: Mathematical model of the System changes with time, temp, and environment. In words hysterias property occurs.
- 13. 1.3 Essential Considerations in Embedded design • ResponseTime ‐‐ RealTime Systems • Area • Cost • Portability • Low Power (Battery Life)
- 14. 2.1 General Purpose Processors • 16/32‐bit data path. • Contains ALU(arithmetic logic unit) • Contains Registers that is used in arithmetic and logic operations. • It contains PC(program counter). • Designed for a wide range of applications . • Examples: ARM, PowerPC, MIPS, 68K, x86.
- 15. 2.2 Microcontrollers • The workhorse of industrial electronics. • Designed for standalone operation. • Include a processing unit of 8‐bit, 16‐bit, 32‐bit. • Included memories (RAM, ROM), I/O, buses and peripherals, depending on the application designed for (LIN , CAN , Ethernet , I2C , SPI,…etc ).
- 17. 2.3 Embedded Software Characteristics • Highly configurable. • Shorter development cycle. • Easier in versions updates. • Cheaper. • Constrained to processor speed which may or may not satisfy real time applications.
- 18. 2.4 Difference between Microcontroller and Microprocessor Microprocessor: Microcontrollers: Is a typical Personal Computer where devices are attached to the CPU, using hard‐wired connections, which makes the system more flexible.That means you can add more memory, change capacity of hard drives, add or remove CD‐ROMs, sound cards, etc. Is a single chip, self‐contained computer which incorporates all the basic components of a personal computer on a much smaller scale. Most of these components are built exactly within the same package. Some of these components are: CPU, RAM, ROM, Timers, I/O, etc.
- 19. 2.5 Microcontroller in a System • Microcontrollers don’t work alone in the circuit it must interfaces with other on chip devices. • Microcontroller can accept inputs from some components and provide outputs to other components within any given system. • Differences in requirements, make the manufacturers produce different microcontrollers with different memory sizes, number of I/O lines and number of integrated peripheral devices. Otherwise they are all similar to use.
- 20. 2.5 System On Board Generic Embedded System Structure
- 21. 3.0 Microcontroller main components • Central processing unit (CPU). • Buses. • Memory units. • Input and Output (GPIO or DIO).
- 22. 3.1Central Processing Unit(CPU) • The unit which monitors and controls all processes inside the microcontroller. It consists of several smaller units. The most important units are:
- 23. 3.1Central Processing Unit(cont’d) • Arithmetical logical unit (ALU): performs all mathematical and logical operations upon received data. • Instruction Decoder Is a part of electronics that recognizes program instructions and runs other circuits as a result.The “instruction set” which differs from microcontroller family to another expresses the abilities of this circuit.
- 24. 3.1Central Processing Unit(cont’d) • BUS – Physically, the bus consists of 8, 16 or more wire. –There are two types of buses: address and data bus.The first one consists of as many lines as necessary for memory addressing.The other one is as wide as data width, it may be 8, 16, or 32 bits or wires wide.
- 25. 3.2CPU Main Registers • The numbers and names of registers vary drastically • among microcontrollers. However there are certain • registers which are common to most of microcontrollers, • although the names may vary.
- 26. CPU Main RegistersIndex register Program counter Register Special Function Registers (SFR registers) Stack pointer –The index register is used to specify an address when a certain addressing mode is used. – It is also known as the pointer register. – Perhaps the most important CPU register is the program counter(PC). –The PC holds the address of the next instruction in program memory space, which the CPU will process. As each instruction is fetched and processed by the ALU, the CPU increments the PC and thereby steps through the program stored in the program memory space. Their bits are connected (literally) to internal circuits such as timers, A/D converter, oscillators and others, which means that they are directly under command of the operation of the microcontroller. – Contains the address of the next location in the stack. – Decremented when data is pushed into the stack and incremented when data is popped out from the stack (and may be vice versa for some processors).
- 27. 3.3 CPU Architecture • There are two basic types of architecture: Harvard andVon Neumann. • Microcontrollers most often use a Harvard or a modified Harvard‐based architecture.
- 28. 3.3 CPU Architecture(cont’d) • Von‐Neumann architecture –Von Neumann architecture has a single, common memory space where both program instructions and data are stored. –There is a single data bus which fetches both instructions and data.
- 29. 3.3CPU Architecture(cont’d) • Von‐Neumann architecture – Each time CPU fetches a program instruction it may have to perform one or more read/write operation from/to data memory space. It must wait until these subsequent operations are complete before it can fetch and decode the next program instruction.
- 30. 3.3 CPU Architecture(cont’d) • Harvard Architecture – Harvard architecture computers have separate memory areas for program instructions and data. – One bus is a 8‐bit wide and connects CPU to RAM memory.The other bus consists of several lines (12, 14 or 16) and connects CPU to ROM memory.
- 31. 3.3 CPU Architecture(cont’d) • Harvard Architecture –The CPU can read an instruction and perform a data memory access at the same time. –This speeds up execution time but increases the cost of more hardware complexity
- 32. 3.4 Memory Unit • Memory is a part of the microcontroller used for data storage. • There are different types of memory within the microcontroller: – ROM memory (Read Only Memory) – RAM memory (Random Access Memory).
- 33. 3.4 RAMVS ROM Comparison chart RAM ROM Definition Random Access Memory or RAM is a form of data storage that can be accessed randomly at any time, in any order and from any physical location., allowing quick access and manipulation. Read-only memory or ROM is also a form of data storage that can not be easily altered or reprogrammed. Stores instructions that are not necessary for re-booting up to make the computer operate when it is switched off.They are hardwired. Stands for Random Access Memory Read-only memory Use RAM allows the microprocessor/controller to read data quickly to run applications. It allows reading and writing. ROM stores the program required to initially boot the computer. It only allows reading. Volatility RAM is volatile i.e. its contents are lost when the device is powered off. It is non-volatile i.e. its contents are retained even when the device is powered off. Types The two main types of RAM are static RAM and dynamic RAM. The types of ROM include PROM, EPROM and EEPROM.
- 34. 3.5 HOW all of this work together? • The crustal is the heart of the Microcontroller which is the brain of the system. • It gives the microcontroller the operating frequency(speed of microcontroller), and the clock reference where it can shift from instruction to another.
- 35. 3.6 Input and Output(GPIO or DIO)
- 36. 3.6 Input and Output (cont’d) • The microcontroller has to be connected to additional electronics, peripherals. • For that reason, each microcontroller has one or more registers (called “port” in this case) to which it’s connected. • Suppose you want your device to turn on and off three signal LEDs and simultaneously monitor logic state of five sensors or push buttons to the microcontroller pins.
- 37. 3.6 Input and Output (cont’d) • low‐current consumption (10‐20 mA). • Each I/O port is under control of another SFR, which means that each bit of that register determines state of the corresponding microcontroller pin.
- 38. 3.7 Other peripherals • ADC(Analog to Digital Converting). • Timers. • Serial protocols(SPI,UART,I2C…etc). • Comparators.
- 39. 4.0 Summary • Microcontroller is the brain of the embedded system. • The oscillator is the heart that the makes the microcontroller executes instructions. • The Code is written/burned in the ROM. • Microcontroller writes and reads the Data through processing in the RAM. • The Data is transferred between the CPU, memory, and other peripherals through BUS. • There are a lot of microcontroller peripherals that makes microcontrollers different from each other.
- 41. Any Questions?