...The difference between Interrupts and Traps are simple. Interrupts are hardware interruptions as to where Traps are software – invoked interrupts. Hardware interrupts are program controlled interruptions produced by some event external to the CPU. This stops the CPU from executing the code it was already running and to jump to the event that generated the interrupt. These type of interrupts can come from numerous sources, such as, expansion cards, timer chip, keyboards, and mouse, as well as peripheral devices. Most often, hardware interruptions do not ever occur because of event related program execution. When and interrupt occurs, the CPU is sent an interrupt request by the interrupt event, in order to provide service needed by the device and then returns to the normal program. Most often when a hardware interrupt occurs the CPU starts interrupt server routine (ISR) and other hardware interrupts are disabled. The sole purpose of a Trap is to provide a fixed subroutine and can be identified as a transfer of control that is normally incorporated by the programmer. When a trap occurs, the CPU stops what is it doing like it does when an interrupt occurs, then it saves the context before jumping to the suitable trap routine. Then it completes and restores the context and continues execution. Interrupts are a very important part of computer design. All computers have their own interrupt structure, which most of the functions are the same. An interrupt has to transfer control...
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...Traps are handled by an intricate loop. When the trap is called it executes something similar to a jump routine. With Pep/8 machines the instructions DECI, DECO, and STRO all call a trap. All content of the registers is pushed onto the system stack. Once the trap handler is complete control is returned to the application. “A program during execution is called a process” (Warford, 2010, p. 397). When the trap is called the process is suspended. The operating system takes over to execute the trap handler. The process control block (PCB) is the block of memory that contains a copy of the trapped process’s registers. The statement RETTR returns control back to the process once the trap has completed. Any changes made in the PCB will change the registers in the CPU. The DECI trap handler converts ASCII characters to bits in two’s complement. The handler will allocate six local variables on the stack. The variables are: total, valAscii, is0vfl, isNeg, state, and temp. A finite state machine loop is started. The bits go through the trap handler and bits are masked and multiplied with left-shift operations until the proper data is found. The DECO trap handler outputs decimal numbers. The trap is called and the data goes through a loop. The data is accessed with a load whereas the DECI is stored. The value is determined by repeatedly subtracting the variables place from remain. The trap handler for STRO uses stack-indexed deferred addressing. This process acts like...
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...in Clustered system and in Multiprocessing system LAN etc is not required. The aim is high availability in clustered system whereas in multiprocessing it is time saving. In order for two machines to provide a highly availability service, the state on the two machines should be replicated and should be consistently updated. When one of the machines fails, the other could then takeover the functionality of the failed machine. Answer 1.19: An interrupt is generally initiated by the hardware (devices like the hard disk, graphics card, I/O device, etc). The purpose of interrupts is to causes the CPU to stop what its doing, save its context, jump to the appropriate interrupt service routine, complete it, restore the context, and continue execution. For example, a serial device may assert the interrupt line and then place an interrupt vector number on the data bus. The CPU uses this to get the serial device interrupt service routine, which it then executes as...
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...from ever knowing who shot the fatal shot. If the bullet hits the heart, the inmate will die almost instantly. If the bullet does not hit the heart, the inmate will be left in the execution chair until they bleed to death. Lethal Injection, which is used in every single state that carries this sentence, is thought to be the most humane. Strapped to a gurney, a medical professional will then insert one of two needles, the second being for back up, in a useable...
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...Tutorial On Introduction to 8085 Architecture and Programming Contents 1. Internal architecture of 8085 microprocessor 2. 8085 system bus 3. 8085 pin description. 4. 8085 functional description. 5. Programming model of 8085 microprocessor 6. Addressing modes. 7. Instruction set classification. 8. Instruction format. 9. Sample programs. 1. Internal Architecture of 8085 Microprocessor Control Unit Generates signals within uP to carry out the instruction, which has been decoded. In reality causes certain connections between blocks of the uP to be opened or closed, so that data goes where it is required, and so that ALU operations occur. Arithmetic Logic Unit The ALU performs the actual numerical and logic operation such as ‘add’, ‘subtract’, ‘AND’, ‘OR’, etc. Uses data from memory and from Accumulator to perform arithmetic. Always stores result of operation in Accumulator. Registers The 8085/8080A-programming model includes six registers, one accumulator, and one flag register, as shown in Figure. In addition, it has two 16-bit registers: the stack pointer and the program counter. They are described briefly as follows. The 8085/8080A has six general-purpose registers to store 8-bit data; these are identified as B,C,D,E,H, and L as shown in the figure. They can be combined as register pairs - BC, DE, and HL - to perform some 16-bit operations. The programmer can use these registers to store or copy data into the registers by using data copy instructions. Accumulator ...
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...Support your answers with 2-3 reasons. Ans: FCFS is used due to Processes have equal execution times. No need to interrupt the processes. Q3:The OS is a giant routine library. There are functions buried deep inside its bowels ready to becalled by your user-level program, sitting indexed by the IVT. Whenever a call to these system-level functions is made, the caller’s address is pushed on a system stack, and when the function is done doing what it was supposed to do, that return address is popped. The usual OS land security policy requires that you are required to put a single gatekeeper at the stack, logically speaking, to control access to either the push or the pop events. With which event would you associate that gatekeeper, and why? Ans: Pop because their value is inside the stack then gatekeeper allows the value from stack to be pop. Q4: Categorize following events as interrupt or trap: 1) Upon modification of the program counter (PC) register, a nonexistent programed memory location, unimplemented in the microcontroller, is addressed. Answer: Event categorize as address error trap. 2) The stack pointer (SP) value exceeds the value of the SPLIM (Stack Pointer LIMit – set by the user) register, i.e. the stack is exceeded from the upper side. Answer: Event categorize as stack error trap. 3) User is trying to access the instruction y = t /0. Answer: Event categorize as arithmetic error trap 4) Ahmed is trying to open a document by double clicking on mouse. Answer: interrupt...
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...file to add the execute bit for user, group, and owner (sudo chmod 755 week4.scr). 3. Edit the file using Gedit 4. Enter the following lines of shell script into the file (just copy and paste): #!/bin/bash trap “echo You cannot press THAT key” SIGINT SIGTERM count=1 echo "Start of week4 script" while [ $count -le 10 ] do echo "Loop #$count" sleep 5 count=`expr $count + 1` done echo "end of the program” 5. Save the file 6. Run the script to make sure you have no syntax errors: • ./week4.scr • NOTE: If you have syntax errors, you mistyped something. The script must run with NO syntax errors before you can move on. If you need help, ask. 7. Run the script and verify that you are trapping the SIGINT (signal 2) and SIGTERM (signal 15) signals properly: • ./week4.scr • Open a NEW, second Terminal window. o ps –ef | grep week4.scr ▪ This will obtain the PID of your script o kill -2 PID ▪ Verify that your trap message is displayed in the FIRST Terminal window o kill -15 PID ▪ Verify that your trap message is displayed in the FIRST Terminal window 8. Take a screen capture of this sequence (FIRST Terminal window only) and paste it here: 9. Run the script again using the `crontab...
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...A Road Map Through Nachos Thomas Narten Department of Computer Sciences Levine Science Research Center Duke University Box 90129 Durham, N.C. 27708-0129 narten@cs.duke.edu January 4, 1995 Abstract Nachos is instructional software that allows students to examine, modify and execute operating system software. Nachos provides a skeletal operating system that supports threads, user-level processes, virtual memory and interrupt-driven input output devices. Nachos is a complex piece of software and it is di cult for beginning students (and instructors) to easily gain on overall understanding of the various system pieces and how they t together. This document provides a road map to understanding the Nachos system. It gives a high-level overview of the source code, focusing on the big picture rather than on the details. It is not intended as a replacement for reading the source code. Rather, it is a companion that is intended to help students (and instructors) overcome the initial learning curve encountered when learning and using the system. Contents 1 Introduction to Nachos 2 Nachos Machine 2.1 2.2 2.3 2.4 Machine Components : : : : : : Interrupt Management : : : : : Real-Time Clock Interrupts : : Address Translation : : : : : : : 2.4.1 Linear Page Tables : : : 2.4.2 Software Managed TLB 2.5 Console Device : : : : : : : : : 2.6 Disk Device : : : : : : : : : : : 1 : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :...
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...- Executive Brief (April 2012) - Introduction Balanced Scorecard is an integrated, organization-wide management system that drives, in an aligned manner, the transformation, improvement and modernization efforts of all hierarchical levels towards the accomplishment of organization’s Strategy. For this reason, Balanced Scorecard is also known as a Strategy Execution system. More precisely, Balanced Scorecard represents a framework for aligned Strategic Planning and for the consistent management of the organizational and individual performance in the execution of the Strategic Plan. Furthermore, Balanced Scorecard is a communication tool that helps each employee better understand where the Strategy drives the organization, what the plan is for reaching that destination and what their departmental and individual measured contribution is to that convergent effort. With such understanding, the employees – whether directly involved in the planned Strategy Execution, or not – can also change and improve the way they perform their daily jobs through micro-decisions that are both convergent and complementary to the execution of organization’s Strategic Plan. BSC History Balanced Scorecard has been launched twenty years ago as a first set of principles for balanced strategic Objectives and Measures/KPIs setting and measurement. The “parents” of Balanced Scorecard are Dr. Robert S. Kaplan, Baker Foundation Professor at Harvard Business School and Dr. David P. Norton, the founder...
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...PROM/IO chip. The 8085A uses a multiplexed Data Bus. The address is split between the higher 8bit Address Bus and the lower 8bit Address/Data Bus. During the first cycle the address is sent out. The lower 8bits are latched into the peripherals by the Address Latch Enable (ALE). During the rest of the machine cycle the Data Bus is used for memory or l/O data. The 8085A provides RD, WR, and lO/Memory signals for bus control. An Interrupt Acknowledge signal (INTA) is also provided. Hold, Ready, and all Interrupts are synchronized. The 8085A also provides serial input data (SID) and serial output data (SOD) lines for simple serial interface. In addition to these features, the 8085A has three maskable, restart interrupts and one non-maskable trap interrupt. The 8085A provides RD, WR and IO/M signals for Bus control. Status Information Status information is directly available from the 8085A. ALE serves as a status strobe. The status is partially encoded, and provides the user with advanced timing of the type of bus transfer being done. IO/M cycle status signal is provided directly also. Decoded So, S1 Carries the following status information: HALT, WRITE, READ, FETCH S1 can be interpreted as R/W in all bus transfers. In the 8085A the 8 LSB of address are multiplexed with the data instead of status. The ALE line is used as a strobe to enter the lower half of the address into the memory or peripheral address latch. This also frees extra pins for expanded interrupt capability. Interrupt...
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...Choices: 1. A plan is a trap laid to capture the ________. Ans.: A) Future 2. It is the function of employing suitable person for the enterprise Ans.: B) Staffing 3. ___________ means “ group of activities & employees into departments” Ans.: D) Departmentation 4. This theory states that authority is the power that is accepted by others Ans.: A) Acceptance theory 5. It means dispersal of decision-making power to the lower levels of the organization Ans.: A) Decentralization 6. This chart is the basic document of the organizational structure Ans.: C) Master Chart 7. Communication which flow from the superiors to subordinates with the help of scalar chain is known as Ans.: B) Downward communication 8. Needs for belongingness, friendship, love, affection, attention & social acceptance are Ans.: D) Social Needs 9. A management function which ensures “jobs to be filled with the right people, with the right knowledge, skill & attitude” Ans.: A) staffing defined 10. It is a process that enables a person to sort out issues and reach to a decisions affecting their life Ans.: D) Counseling Part Two: 1. Differentiate between ‘Administration’ and ‘Management’. Ans.: According to Oliver Sheldon, Administration is the function in industry concerned with the determination of the corporate policy, the co-ordination of finance, production and distribution. Whereas management is the function concerned with the execution of policy...
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...promises but also on whether visible or hidden partners deliver on their promises too. In other words, company’s success depends not just on its own efforts but also on the ability, willingness, and likelihood that the partners that make up its innovation ecosystem succeed as well. Thus, a new perspective must be adopted, a wide lens, with which to assess a company strategy using a new set of tools and frameworks that will expose a company hidden sources of dependence. The Innovation Behind Spot and Avoidable Failure Although great execution is a necessary condition for success, it is not enough. Indeed, while the execution focus draws attention to important aspects of a company strategy (developing customer insight, building core competencies, and beating the competition), it creates a blind spot that hides key dependencies that are equally important in determining success and failure. Examples: Philips Electronics despite sterling execution and rave reviews, Philips's high-definition TV flopped, because its value creation depended on other innovations (the high-definition cameras and transmission standards necessary to make high-definition TV work) that failed to arrive on time. Sony it launched its e-reader to market before its rivals but even a great e-reader cannot succeed in a market where customers have no easy access to e-books. Johnson Controls it developed a new generation of electrical switches and sensors, but until architects, electricians, and a host of other...
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...the processes in doing so. For the processes to access and make use of these services, system calls are used. What is Linux Shell? What is Shell Script? Linux shell is a user interface used for executing the commands. Shell is a program the user uses for executing the commands. In UNIX, any program can be the users shell. Shell categories in Linux are: Bourne shell compatible, C shell compatible, nontraditional, and historical A shell script, as the name suggests, is a script written for the shell. Script here means a programming language used to control the application. The shell script allows different commands entered in the shell to be executed. Shell script is easy to debug, quicker as compared to writing big programs. However the execution speed is slow because it launches a new process for every shell command executed. Examples of commands are cp, cn, cd. What are Pipes? Explain uses of pipes. A pipe is a chain of processes so that output of one process (stdout) is fed an input (stdin) to another. UNIX shell has a special syntax...
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...Crimes Punishable by Death Penalty According to the statistic from year 1608 to 2002, the top 5 executions by crime are murder, rape, slave revolt, burglary, and robbery. 81.8% of the crime is murder cases. Rape cases contain 6.7%, Slave revolt cases is 1.9%. Next, Burglary is 1.7%. Lastly, robbery cases is 1.1%. Besides that, there are still other criminal action which will lead to death penalty. For example, crime of treason, terrorism and drug trafficking. Different country have different law judge the prisoner depends on the criminal action that they did. Methods of Execution There are 5 authorized methods to execute death penalty. First is lethal injection, 85% of the countries would use this method to execute the crime. When this method is used, the condemned person is usually bound to a gurney and a member of the execution team positions several heart monitors on this skin. Two needles are then inserted into usable veins, usually in the inmates’ arms. Long tubes connect the needle through a hole in a cement block wall to several intravenous drips. The first is a harmless saline solution that is started immediately. Then, at the warden's signal, a curtain is raised exposing the inmate to the witnesses in an adjoining room. Then, the inmate is injected with sodium thiopental - an anesthetic, which puts the inmate to sleep. Next flows pavulon or pancuronium bromide, which paralyzes the entire muscle system and stops the inmate's breathing. Finally, the flow of potassium...
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...12/19/14 Systematic Traps and Biases in Professional Judgment: Insights from Research in Psychology Douglas F. Prawitt, PhD, CPA Brigham Young University The Emerging Science of Judgment • Rapid change, increased complexity in business • Greater importance of professional judgment The Emerging Science of Judgment • Rapid change, increased complexity in business • Greater importance of professional judgment Fortunate coincidence: A critical mass of insight on human judgment emerging— 30+ years of research in economics, management, and cognitive psychology bearing fruit 12/19/14 Ambitious goals for today • Introduce a model—common vocabulary and framework • Explain importance of proactive “reframing” and identify common pitfalls in applying the judgment model • Identify and explain judgment biases, and how to mitigate their impact Visual Perception Professional Judgment: The process of reaching a conclusion where there are a number of possible alternative solutions and uncertainty is involved. 12/19/14 Professional Judgment: The process of reaching a conclusion where there are a number of possible alternative solutions and uncertainty is involved. ‐‐A simple process‐oriented professional judgment framework is helpful… The KPMG Professional Judgment Framework © 2010 KPMG International Cooperative (“KPMG International”), a Swiss entity. Member firms of the KPMG network of independent firms are affiliated...
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