IT2A4 EMBEDDED SYSTEMS

Transcription

1 IT2A4 EMBEDDED SYSTEMS UNIT I INTRODUCTION TO EMBEDDED SYSTEMS Definition and Classification Overview of Processors and hardware units in an embedded system Software embedded into the system Exemplary Embedded Systems Embedded Systems on a Chip (SoC) and the use of VLSI designed circuits UNIT II DEVICES AND BUSES FOR DEVICES NETWORK I/O Devices - Device I/O Types and Examples Synchronous - Iso-synchronous and Asynchronous Communications from Serial Devices - Examples of Internal Serial- Communication Devices - UART and HDLC - Parallel Port Devices Sophisticated interfacing features in Devices/Ports- Timer and Counting Devices - 12C, USB, CAN and advanced I/O Serial high speed buses- ISA, PCI, PCI-X, cpci and advanced buses. UNIT III PROGRAMMING CONCEPTS AND EMBEDDED PROGRAMMING IN C, C++ Programming in assembly language (ALP) vs. High Level Language - C Program Elements, Macros and functions -Use of Pointers - NULL Pointers - Use of Function Calls Multiple function calls in a Cyclic Order in the Main Function Pointers Function Queues and Interrupt Service Routines Queues Pointers Concepts of EMBEDDED PROGRAMMING in C++ - Objected Oriented Programming Embedded Programming in C++, C Program compilers Cross compiler Optimization of memory codes. UNIT IV REAL TIME OPERATING SYSTEMS PART - 1 Definitions of process, tasks and threads Clear cut distinction between functions ISRs and tasks by their characteristics Operating System Services- Goals Structures- Kernel - Process Management Memory Management Device Management File System Organization and Implementation I/O Subsystems Interrupt Routines Handling in RTOS, REAL TIME OPERATING SYSTEMS : RTOS Task scheduling models - Handling of task scheduling and latency and deadlines as performance metrics Co-operative Round Robin Scheduling Cyclic Scheduling with Time Slicing (Rate Monotonics Co-operative Scheduling) Preemptive Scheduling Model strategy by a Scheduler Critical Section Service by a Preemptive Scheduler Fixed (Static) Real time scheduling of tasks - INTER PROCESS COMMUNICATION AND SYNCHRONISATION Shared data problem Use of Semaphore(s) Priority Inversion Problem and Deadlock Situations Inter Process Communications using Signals Semaphore Flag or mutex as Resource key Message Queues Mailboxes Pipes Virtual (Logical) Sockets Remote Procedure Calls (RPCs).

2 UNIT V REAL TIME OPERATING SYSTEMS PART - 2 Study of Micro C/OS-II or Vx Works or Any other popular RTOS RTOS System Level Functions Task Service Functions Time Delay Functions Memory Allocation Related Functions Semaphore Related Functions Mailbox Related Functions Queue Related Functions Case Studies of Programming with RTOS Understanding Case Definition Multiple Tasks and their functions Creating a list of tasks Functions and IPCs Exemplary Coding Steps.

3 IT2A4 EMBEDDED SYSTEMS 2 MARKS UNIT-I INTRODUCTION TO EMBEDDED SYSTEMS 1. What is System? The system is a way of working, organizing or doing some task or series of tasks by following plan, program and set of rules. E.g: time display system, Automatic cloth washing system. 2. Define Embedded Systems. An embedded system is one that has computer-hardware with software embedded in it as one of its most important component. Software embedded into hardware is known as embedded systems. E.g: Mobile Phones, Elevator, Computer, etc. 3. What are the components of embedded system hardware? Processor Program memory and data memory Timers Serial communication ports Input devices Output devices Power suply, Reset and Oscillator Circuits 4. Classification of embedded system. Small Scale Embedded Systems Medium Scale embedded Systems Large Scale Embedded Systems 5. Define Processor. Processor is the heart of the system. A processor implements a process or processes as per the commands given to it. 6. Specify the 2 essential units of the processor in a system. Program Flow Control Unit (CU) Execution Unit (EU)

4 7. What are the types of General Purpose Processor? Microprocessor Microcontroller Embedded Processor Digital Signal Processor (DSP) Media Processor 8. Define Microprocessor. A microprocessor is a single VLSI chip that has a CPU and may also have some other units that are additionally present and that result in faster processing of instructions. 9. Define Microcontroller. A microcontroller is a single-chip VLSI unit which, though having limited computational capabilities, possesses enhanced input-output capabilities ana a number of on-chip functional units. 10. What is Clock? A fixed frequency pulses that an oscillator circuit generates and that controls all operations during processing and all timing references of the system. 11. What is the process of Reset? A processor state in which the processor registers acquire initial values and from which starts an initial program; this program is usually the one that also runs on power up. 12. Define Watchdog timer. A timer the timeout from which resets the processor in case the program gets stuck for an unexpected time. 13. What is ROM image? The final stage software embedded into hardware is known as Rom image. 14. Define Assembler. An assembler translates the assembly software into machine codes using a step called assembling. 15. Define Linker. Linker links the codes with the other required assembled codes. Linking is necessary because of the number of codes to be linked for the final binary file. 16. Define Loader. Loader program performs the task of relocating the codes after finding physical RAM addresses available at a given instant.

5 17. What is the use of Locator? A program called locator reallocates the linked file and creates a file for permanent location of codes in a standard format. 18. Define Compiler. A compiler assembles the codes according to the processor instruction set and other specifications. 19. What is Device driver? A device driver is software for controlling, receiving and sending a byte or a stream of bytes from or to a device. 20. Define multitasking. A task may share the memory with other task. A processor may process multiple tasks separately or concurrently.

6 UNIT II DEVICES AND BUSES FOR DEVICE NETWORK 1. What are the types of I/O devices? Serial Input, Output Serial UART Input, Output Parallel Port Single Bit Input, Output Parallel Port Input, Output 2. Give some example for Serial UART Input. Keypad, Mouse, Keyboard, Modem, Character inputs on serial line. 3. Types of communication. Synchronous Iso-Synchronous Asynchronous 4. Define Synchronous Communication. When a byte or a frame of the data is received or transmitted at constant time intervals with uniform phase differences, the communication is called as synchronous. 5. Define Isosynchronous Communication. Communicationin which constant phase difference is not maintained between the frames but maintained within a frames. 6. Define Asynchronous Communication. A communication in which a constant phase difference is not maintained and the clocks that guide the transmitter and receiver are separate. The time interval is not fixed. 7. Give short notes on HDLC. HDLC represents a High Level Data Link Control. This is an international standard protocol for a data link network. It is used for linking data from point to point and between multiple points. 8. Specify some states in a Timer. Reset State Initial Load State Present state Overflow State Overrun State

7 9. What is the Use of timer devices? Real Time clock ticks. Initiating an event after a present delay time. Capturing the count vale at the timer. Scheduling of various tasks. 10. Define I 2 C Bus. The two IC s are mutually network through a common bus I s known as I 2 c bus. It has two lines for carry signals. One line is for clock and one is for bi-directional data. 11. Define CAN Bus. The number of devices are networked and controlled through a network bus. It is mainly used in automotive electronics. 12. What is USB Bus? The Universal Serial Bus (USB) is a bus between a host system and a number of interconnected peripherals. The serial devices are scanner, keyboard, printer, etc. 13. Give some example for Advanced Serial High Speed Buses. IEEE XAUI XBI SONET OC-48 SONET OC Define ISA Bus. It is a standard bus based on IBM standard architecture. 15. What are PCI and PCI/X Bus? PCI A standard bus used as Peripheral Component Interconnect bus PCI/X A standard bus used as PCI Extended Bus 16. Define Master Slave Communication. A communication between two processors when one processor guides the transmission of the bits to a slave after receiving acknowledgement from the address slave. 17. Define Watchdog Timer. An important timing device in a system that resets the system after a predefined timeout.

8 18. Handshaking signals. The signals before storing the bits at the port buffer or before accepting the bits from the port buffer. 19. What are the protocols used in Advanced Parallel High Speed Buses? GMII XGMI CSIX-1 RapidIO 20. Explain the characteristics of parallel port devices. A port device may have multi-byte data input buffer. A port may have a data Direction register (DDR). It is bidirectional.

9 UNIT III PROGRAMMING CONCEPTS AND EMBEDDED PROGRAMMING IN C, C++ 1. What are the advantages of assembly language coding? It gives a precise control of the processor. The machine codes are compact. A few assembly instruction device driver codes may need only. 2. What are the advantages of high level language? Repetitive coding redundant. Use of standard library function. Modular programming approach. Type checking. Control structures. Portability. 3. Define Modular programming approach. It is an approach in which the large modules are divided into number of sub modules and each module are executed separately. 4. Bottom Up design. Programming is first done for the sub modules of the specific and distinct actions. 5. Top-Down design. It is another programming approach, in which the main program is first designed, then its modules, sub-modules, and finally the functions. 6. What is the Inclusion files used? Including Codes files. Including string data files. Including initial data files. Including header files. Including basic variable files. 7. Define source files. Source files are program files for the application software. The source files need to be compiled. The first function from where the processing will start is known as main function. It codes starts with void main ().

10 8. What is the use of configuration files? Cofiguration files are the files for the configuration of the system. Eg: #include os_cfg.h 9. What are the two types of preprocessor directives? Preprocessor Global Variables. Preprocessor Constants. 10. What are C program elements? Inclusion files. Source files. Configuration files. Preprocessor directives. 11. What are program elements? Dta types. Data structures. Modifiers. Statements. Loops. 12. Define Macro function. Executes a named small collection of codes with values passed by calling program through its aguments. 13. What is Recursive function? A function that calls itself is known as recursive function. It may be reentrant also. 14. Define Queue. It is a data structure with a series of element with the first element waiting for an opration. An operation can be done only in the first in first out (FIFO) mode. 15. What are the steps involved in function calls? Declaring a function. Defining statements in the function. Call to a function. 16. Define Reentrant function. Reentrant function is usable by several tasks and routines synchronously (at the same time). This is because all its argument values are retrievable from the stack. 17. What are the 5 flags used in queue? Qerrorflag hearderflag

11 trailingflag CirQuflag PolyQuFlag 18. How an object is characterized? An identity (a reference to a memory block) A state ( its data, property, fields and attributes) A behavior (method or methods) 19. Types of methods. Method overloading Method overriding 20. Define Method overloading. Methods can have same name in the inherited class. This is called as method overloading. 21. Define Method Overriding. Methods can have same name as well as same number of types of arguments in the inherited class. 22. What are the disadvantage of C++? Template. Multiple Inheritance. Exceptional handling. Virtual base classes. 23. Define Cross-compiler. The cross compiler runs on a host, but develops the machine codes for the targeted system.

12 UNIT IV REAL TIME OPRATING SYSTEMS PART-1 1. Define process. A process defines a sequentially executing (running) program and its state. The state during running of a process is represented by its status (running, blocked or finished), its control block calls as process control block (PCB). 2. Define task. An application program can also be defined as a program consisting of the tasks and task behaviors in various states that are controlled by scheduling mechanisms. 3. What are task states? Idle state Ready state Running state Blocked state 4. Define thread. Thread is a small executable unit in a program. A process may consist of one or multiple threads. 5. Write the layer structure of OS. Application software Application Programming Interface (API) System software Hardware OS Hardware 6. What are the 2 types of modes used in OS? User mode The user process is permitted to run and use only a subset of function. Supervisory mode The OS runs in protected mode. 7. Define Kernel. Kernel is the basic structural unit of OS. It can be defined as a secured unit in OS. The OS is the middle layer between the application software and system hardware. An OS includes the kernel as the structural unit.

13 8. Write the 2 types of request methods in OS. Message A process running on user mode generates the message. System-call A call to a function at the OS. 9. Define Memory Allocation. When a process is created, the memory manager allocates the memory addresses to it by mapping the process-address space. 10. What are the functions of device management? Device Detection and Addition. Device Deletion. Device Allocation and Registration. Device Buffer Management. 11. Write the two types of file system. Block File System. Byte Stream File System. 12. Define Real Time Operating System. Operating syatem with real time task scheduling, interrupt-latency control, synchronisation of tasks with IPCs, predictable timing and synchronisation behaviour of the system. 13. Define Fixed Block Allocation. Memory address space is divided into blocks with processes having small address spaces getting a lesser number of blocks and processes with big address spaces getting a larger number of blocks. 14. What is pre-emptive scheduling? A scheduling algorithm in which a higher priority task is forced to block by the scheduler to let a higher priority task run. 15. What are the methods used in fixed real time scheduling? Simulated annealing method Heuristic method Dynamic programming model 16. Write the three solutions for shared data problem. Use modifier volatile

14 Use reentrant function Put a shared variable in a circular queue 17. Define signal function. One way for messaging is to use an OS function signal(). It is provided in Unix, Linux and several RTOSes. A hardware mechanism sends the interrupt to the OS, task or the OS itself sends signals. 18. Define Mutex. The special variable and mechanism used to take note of certain action to prevent any task or process from proceeding further and at the same time let another task exclusively proceed further. 19. Define Pipe. A device for use by the task for sending the messages and another task using the device receives the messages as streams. A pipe is a unidirectional device. 20. Define Semaphore. A special variable operated by the OS functions which are used to take note of certain actions to prevent another task or process from proceeding further.

15 UNIT V REAL TIME OPERATING SYSTEMS PART-2 1. Give some example for RTOS. Linux µcos-ii VxWorks Windows CE QNx VRTX PalmOS 2. What is the use of void OSInit (void) and void OSStart (void)? void OSInit (void) Used at the beining prior to OSStart() void OSStart (void) Used after the OSInit() and task create function 3. Define Locking OS scheduler. OSSchedlock() disables preemption by a higher-priority task. This function inhibits preemption by higher-priority task, but does not inhibit interrupt. If an interrupt occurs then locking enables return of OS control to that task, which executes this function. The control returns to the task after any ISR completes. 4. What are the steps involved in task service? Creating a task Suspending a task Resuming a task 5. Specify time delay functions. Void OSTimeDly Unsigned byte_ostimedlyresume Void OSTimeDlyHMSM 6. Define queue related functions. A mailbox communicates a pointer for a message, which may be larger or smaller. By using a queue, we can communicate an array of message pointers from the tasks. 7. What is the use of VxWorks? Multitasking environment

16 Supports ability to run two concurrent OS Multiple file systems Watchdog timers 8. Write any functions for task state transitions. taskresume() tasksuspend() semgive() taskdelay() tasksuspend() exit() taskdelete() 9. What is exception handling? Executing a function on receiving a signal. Error is also handled by using an exception-handling function. 10. Define mailbox. An IPC in the event control block into which a task posts the messages at the tail pointer or urgent messages at the front pointer, which are retrieved by another task waiting for that. 11. Define TCB. TCB is a Task control block, which has the task parameters so that on task switching the parameters remain saved and when RTOS re-switches it back, the task can run from the point at which it left. Task is thus an independent process. 12. Task creation. Task is allotted a TCB and an identity. Creation also initiates and schedules on creation in MUCOS. 13. What is mean by resource key? A semaphore that resets on the start of execution of a critical region code and sets on finishing these. 14. What is the use of system timer? A system clock that can be set to interrupt at present interwals. The time is updated regularly and the system interrupts regularly. RTOS also gets control of CPU to examine if any preemption or rescheduling is needed.

17 15. Define IPC and specify some IPC functions. IPC Inter Process Communication Some of the functions are, sembcreate() semmcreate() semdelete() semtake() 16. What is the function used to create pipe device in IPC? pipedevcreate() 17. What is the specification of ACVM? Alphanumeric keyboard Three line LCD display Coin insertion slot Delivery slot Internet connection port 18. What are the 2 inputs of ACVM? Coins of different denominations through a coin slot User commands 19. What is the purpose of digital camera? Digital recording and display of pictures. Processing to get the pictures of required brightness, contrast and color. Permanent saving of a picture in a file. Transfer files to a computer through a port. 20. Write the design metrics of digital camera? Power dissipation. Resolution. Performance. Process deadlines User interfaces Engineering cost Manufacturing cost

18 6 MARKS UNIT-I INTRODUCTION TO EMBEDDED SYSTEMS 1. Explain about the components used in system. A microprocessor A large memory Primary memory Secondary memory Input units Output units Networking units I/O units 2. What are the Components of embedded system? Processor Program memory and data memory Timers Serial communication ports Input devices Output devices Power suply, Reset and Oscillator Circuits 3. Explain about the Classification of embedded system. Small Scale Embedded Systems Medium Scale embedded Systems Large Scale Embedded Systems 4. What are the types of memories used in Embedded system? Internal RAM RAM at system on chip Internal caches at microprocessor External RAM Flash / EEPROM ROM / PROM Memory addresses at the system port

19 5. Write short notes on Components in an Exemplary SoC-Smart Card with diagram. ASIP RAM ROM EEPROM Timer and Interrupt Controller Interfacing circit for I/Os

20 UNIT II DEVICES AND BUSES FOR DEVICE NETWORK 1. Types and Examples of I/O Devices. Serial Input, Output Serial UART Input, Output Parallel Port Single Bit Input, Output Parallel Port Input, Output 2. Explain about I 2 C Bus. The two IC s are mutually network through a common bus I s known as I 2 c bus. It has two lines for carry signals. One line is for clock and one is for bi-directional data. Data Integrated Circuit 2 Clock Integrated Circuit 1 Data Clock Clock Integrated Circuit 3 Data 3. Explain ISA Bus. It is a standard bus based on IBM standard architecture. Addresses allocated are hex F. Reserved address from peripherals. Display monitor port are within hex F. 4. What is the difference between PCI and PCI/X Buses? PCI A standard bus used as Peripheral Component Interconnect bus PCI/X A standard bus used as PCI Extended Bus

21 5. Write short notes about USB and Advanced Serial High Speed Buses. The Universal Serial Bus (USB) is a bus between a host system and a number of interconnected peripherals. The serial devices are scanner, keyboard, printer, etc. IEEE XAUI XBI SONET OC-48 SONET OC-192

22 UNIT III PROGRAMMING CONCEPTS AND EMBEDDED PROGRAMMING IN C, C++ 1.Write short notes about Inclusion files in C program elements. Including Codes files. Including string data files. Including initial data files. Including header files. Including basic variable files. 2.Explain about program elements. Macro function Main function Reentrant function Interrupt service routine Task Recursive function 3.What is the Use of Pointer and NULL Pointers? Unsigned byte *porta Void *portadata #define porta Unsigned byte *porta = &portadata Unsigned short *timer1 #define NULL(void*) 0x000 4.What are the steps involved in Function Calls? Declaring a function. Defining statements in the function. Call to a function. Passing the values. 5.What is Reentrant function? What are the conditions used in Reentrant function? Reentrant function is usable by several tasks and routines synchronously (at the same time). This is because all its argument values are retrievable from the stack. All the arguments pass the values and none of the argument is a pointer. When an operation is not atomic, that function should not operate on any variable. That function does not call any other function that is not itself Reentrant

23 UNIT IV REAL TIME OPRATING SYSTEMS PART-1 1. What are the goals of operating system? Facilitating easy sharing of resources as per schedule and allocations. Facilitating easy implementation. Maximizing system performance. Providing management function. Providing portability. Providing interoperability. Providing common set of interfaces. 2.Explain about the structure of OS. Application software Application Programming Interface (API) System software Hardware OS Hardware 3.Write short notes about memory management. Memory Allocation Memory Management Fixed block Allocation Dynamic block Allocation Dynamic page Allocation Dynamic Data Memory Allocation Dynamic Address Allocation 4.Explain about process management. Process Creation Management of the Created processes 5.Write short notes on semaphore functions. OSSemCreate OSSemPost OSSemPend OSSemAccept OSSemQuery

24 UNIT V REAL TIME OPERATING SYSTEMS PART-2 1.Write short notes about task service and its exemplary uses. Creating a task Suspending a task 2.Explain time delay functions in RTOS. Delaying by defining a time delay by number of clock ticks. Resuming a delayed task by OSTimeDly. Delaying by defining a time delay in units of hours, minutes, seconds and milliseconds. 3.Explain memory allocation-related functions. Creating memory blocks at a memory address. Getting a memory blocks at a memory address. Querying a memory block. Putting a memory block into a partition. 4.Write semaphore-related function in detail. Creating a semaphore for the IPCs. Waiting for an IPC for semaphore release. Check for availability of an IPC after a semaphore release. Sending an IP after a semaphore release. Retrieve the error information for a semaphore. 5.Explain about mailbox-related functions. Creating a mailbox for an IPC. Check for availability of an IPC after a message at mailbox. Waiting for availability of an IPC for a message at mailbox. Send a message for an IPC through mailbox. Finding mailbox data and retrieving the error information for a mailbox.

25 10 MARKS UNIT-I INTRODUCTION TO EMBEDDED SYSTEMS 1.Explain about the Processor in the System. General Purpose Processor Microprocessor Microcontroller Embedded Processor Digital Signal Processor (DSP) Media Processor Application Specific System processor Multiprocessor System GPP core 2.What are the hardware units used in embedded systems? Power source Clock oscillator circuit Real time clock Reset circuit, watchdog-timer Reset Memories Input, Output, I/O Ports Interrupt Handler DAC and ADC LCD and LED display Keypad / Keyboard Pulse Dialer, Modem Transceiver 3.Explain about the Software used in embedded system. Final Machine Implementable Software for a Product Coding of software in Machine codes Software in Process Specific Assembly Language Software in High Level Language Software for Device Driver and Device Management Software design for Scheduling Multiple Tasks Software Tools in Designing of an Embeded Systems Needed Software Tools in Exemplary Cases Models of Software Designing

26 4.Write brief notes about Embedded System-On-Chip (SOC) and in VLSI Circuit. Exemplary SoC for Cell-Phone ASIP IP Core Embedding a GPP FPGA Components in an Exemplary SoC-Smart Card

27 UNIT II DEVICES AND BUSES FOR DEVICE NETWORK 1.Explain about the Characteristics of Synchronous, Iso-Synchronous and Asynchronous Communication. When a byte or a frame of the data is received or transmitted at constant time intervals with uniform phase differences, the communication is called as synchronous. Communication in which constant phase difference is not maintained between the frames but maintained within a frames. A communication in which a constant phase difference is not maintained and the clocks that guide the transmitter and receiver are separate. The time interval is not fixed. D0 D7 Serial Input Port I0 I7 Clock 2.Explain about Parallel Port Devices with diagram. It contains parallel input port, output port, and a bi-directional port. IORD, IOWR. Port device may have multi byte data input. A port may have a DDR. It may have multiple or alternative functionality. 3.Explain Sophisticated Interfacing Features in Device Ports. Operation voltage level expected for logic state 1 = 5V. Power management can be done at the gate of the device. Port interface used is one drain CMOS. A device connects to a system bus and I/O bus. An IO device consists of multiple gigabyte transceivers. Multiple IO devices can be developed for IO devices. An IO device integrate a Physical Coding Sub layer.

28 4.Explain with example Timer and Counting Devices. States in a Timer Reset State Initial Load State Present state Overflow State Overrun State Use of Timer Device Ten forms of a timer 5.Explain about I 2 C, CAN and USB Buses. The two IC s are mutually network through a common bus I s known as I 2 c bus. It has two lines for carry signals. One line is for clock and one is for bi-directional data. Data Integrated Circuit 2 Clock Integrated Circuit 1 Data Clock Clock Integrated Circuit 3 Data The Universal Serial Bus (USB) is a bus between a host system and a number of interconnected peripherals. The serial devices are scanner, keyboard, printer, etc.

29 UNIT III PROGRAMMING CONCEPTS AND EMBEDDED PROGRAMMING IN C, C++ 1.Explain the Advantages of Assembly language and High level language. Assembly language It gives a precise control of the processor. The machine codes are compact. A few assembly instruction device driver codes may need only. High level language Repetitive coding redundant. Use of standard library function. Modular programming approach. Type checking. Control structures. Portability. 2.Briefly explain C program elements. Include Directive for the Inclusion files Including Codes files. Including string data files. Including initial data files. Including header files. Including basic variable files. Source files Configuration files Preprocessor Directives 3.Explain the Use of function calls and Multiple function calls. Use of function calls Declaring a function. Defining statements in the function. Call to a function. Passing the values. Reentrant function Reentrant function is usable by several tasks and routines synchronously (at the same time). This is because all its argument values are retrievable from the stack.

30 All the arguments pass the values and none of the argument is a pointer. When an operation is not atomic, that function should not operate on any variable. That function does not call any other function that is not itself Reentrant Passing the References Passing argument values through a pointer. 4.Briefly explain Queue. Five flags QerrorFlag Headerflag trailingflag CirQuFlag PolyQuFlag Four Boolean variables headerenable trailingenable CirQuEnable PolyQuEnable Four Unsigned short variable headernumbyte trailingnumbytes CirQuNumByte PolyOuBlockNum 5.Optimization of Memory Needs. Use declaration as unsigned byte. Avoid use of library function. Use assembly code for simple function. Use inline modifiers. Shared data problem does not arise. Combine two functions if possible. Delete function when there is no longer needed.

31 UNIT IV REAL TIME OPRATING SYSTEMS PART-1 1.Define Kernel and its function. Creation to deletion Process structure maintenance Processing resource request Scheduling Interprocess communication Memory management allocation and deallocation Device management Device drivers I/O management Interrupt control mechanism 2.Explain briefly about process management. Process creation Context Process stack pointer Current state Addresses Pointer to the parent process Pointer to the list of daughter process Pointer to a list of resources Management of created processes 3.How a memory management is done in RTOS? Memory Allocation Memory Management after Initial Allocation Fixed block allocation Dynamic block allocation Dynamic page allocation Dynamic data memory allocation Dynamic address relocation Multiprocessor memory allocation Memory protection to OS function Memory protection among the tasks

32 4.What the types used for task scheduling in RTOS? Co-operative Round Robin scheduling Cyclic Scheduling with Time slicing (Rate Monotonics Co-operative Scheduling) Preemptive Scheduling Model Strategy by a Scheduler Critical Section Service by a Preemptive Scheduler Fixed (Static) Real Time Scheduling of Tasks 5.What is shared data problem? Explain the steps to solve shared data problem. Problem of sharing data by multiple task and routines Shared data problem solutions Application of semaphore and shared data problem Elimination of shared data problem Priority inversion problem and deadlock situation

33 UNIT V REAL TIME OPERATING SYSTEMS PART-2 1. What are the queue-related functions for intertask communication? Explain. Creating a Queue for an IPC. Waiting for an IPC message at a queue. Emptying the queue and eliminating all the message pointers. Sending a message pointer to the queue. Sending a message pointer and inserting it at the queue front. Querying to find the message and error information for the queue ECB. 2. Explain about IPC functions. Creating a binary semaphore for the IPCs. Waiting for an IPC for binary semaphore. Sending an IPC after a binary semaphore release. Taking the semaphore multiple times. Creating a mutex semaphore for the IPCs. Creating a counting semaphore for the IPCs. Using POSIX semaphores. Creating a message queue for the message IPCs. Sending an IPC after a message is sent into the queue. Waiting in a queue for availability of message. 3. Explain the design of Automatic Chocolate Vending Machine (ACVM). Requirements. Specifications. Specification Modeling Using UML. ACVM Hardware Architecture. 4. Explain the hardware architecture of a digital camera with neat diagram. CPU. RAM. MUX and ADC. CCD Array. CCDP. Flash memory / ROM. USB port.

34 5. Explain the hardware architecture of an ACVM with neat diagram. State diagram for ACVM tasks. Block diagram of ACVM hardware including microcontroller.