...Timers and Counters Exercise 2.2 1. Define the following timer bits: timer enable, timer timing, and timer done. ANSWER: Timer enable bit: The enable bit is true when the rung input logic is true, and the enable bit is false when the rung input logic is false. When the EN bit is true the timer accumulator is incrementing at the rate set by the timer time base. Timer timing bit: indicates when timing action is occurring and can be used to control timed events in automation applications. Timer done bit: the end of the timing process by changing states from false to true or from true to false depending on the type of timer instruction used. 2. Compare and contrast the true and false states of the timer timing bit for the on-delay timer, the off-delay timer, and the retentive timer. ANSWER: In the true states for all three have the accumulator value is less than the preset value, but for off-delay timer the timer rung is false unlike the retentive timer and on-delay that the timer rung is true. In the false states for all three have the accumulator is equal to or greater than the preset value. Like the true state retentive timer and on-delay timer both have the same condition and that are false if the timer rung is false, but the on-delay timer has other condition that are false if the timer done bit is true. The off-delay has a condition that are false if the timer done is false. 3. What is the difference between a retentive timer and a non-retentive timer? ...
Words: 575 - Pages: 3
...COUNTERS A counter is simply a device that counts. Counters may be used to count operations, quantities, or periods of time. They may also be used for dividing frequencies, for addressing information in storage, or for temporary storage. Counters are a series of FFs wired together to perform the type of counting desired. They will count up or down by ones, twos, or more. In electronics, counters can be implemented quite easily using register-type circuits such as the flip-flop, and a wide variety of classifications exist: • Asynchronous (ripple) counter – changing state bits are used as clocks to subsequent state flip-flops • Synchronous counter – all state bits change under control of a single clock • Decade counter – counts through ten states per stage • Up/down counter – counts both up and down, under command of a control inputMontgomery • Ring counter – formed by a shift register with feedback connection in a ring • Johnson counter – a twisted ring counter • Cascaded counter • modulas counter. Each is useful for different applications. Usually, counter circuits are digital in nature, and count in natural binary. Many types of counter circuits are available as digital building blocks, for example a number of chips in the 4000 series implement different counters. Occasionally there are advantages to using a counting sequence other than the natural binary sequence—such as the binary coded decimal counter, a linear feedback shift register counter, or aGray-code...
Words: 1093 - Pages: 5
...Explain what is meant by 'counterterrorism'. What policy objectives are usually pursued within a counterterrorism grand strategy? Provide suitable examples to illustrate your answer. Counterterrorism involves the “detection and prevention of violent dissident activities by governments, police, security agencies, and military forces to more involved efforts to eliminate support within society for the dissident groups” (Lutz, J & Lutz, B. 2008). Thus, counterterrorism is a combination of multiple façades of government and law enforcement which interact to form a counterterror grand strategy. It is important to draw attention to the differences between a “strategy” and a “grand strategy”. A strategy requires a precisely specified political objective – strategy is a scheme for making the means produce the desired ends (Betts, 2000). A grand strategy on the other hand is far more complex. A grand strategy explains how a state’s full range of resources will be utilised to achieve security (identifying threats and how to minimise or eliminate them) - essentially a grand strategy is “complex, multifaceted, and directed toward a distant time horizon” (Crenshaw, 2004). This essay will explore and discuss the key issues considered while designing a counterterrorism grand strategy, and will provide relevant examples of these issues that have been applied in grand strategies. The major component of an effective counterterrorism grand strategy is the ability of law enforcement and the...
Words: 1545 - Pages: 7
...1. Explain what policy objectives are usually pursued within a counterterrorism grand strategy? Provide suitable examples to illustrate your answer. To create an effective counterterrorism grand strategy, states and governments need to identify what the aim of terrorism upon their state is, the terrorist’s goals and ultimately what they aim to achieve with these acts. Without identifying these areas states can’t introduce and effective counterterrorism strategy. This essay will focus on the policy objectives of the Australian government with their counterterrorism strategy, predominantly the changes made over the last decade as a response to new international terrorism threats. This essay will also look at the United States Counterterrorism policies and their objectives, as they have made some of the most influential decisions regarding counterterrorism over the last decade. In Australia the Criminal Code Act 1995 states that a terrorist act means an action or threat of action where the action causes certain defined forms of harm or interference and the action is done or the threat is made with advancing a political, religious or ideological cause. (Government, 2004) From this definition counterterrorism can be defined as the tactics, practices strategies and techniques used by governments and law enforcement to counteract terrorism acts. States use a variety of goals and subsequently sub-goals that determine their counterterrorism policies. These can vary greatly...
Words: 1446 - Pages: 6
...Terrorism and Counter-terrorism: Similarities and differences in security and risk. Joshua Williams POL192 Perspectives on Security and Terrorism Murdoch University Semester 1, 2014 Utilizing the concepts of risk and security, critically explain the similarities and differences between terrorist strategies and tactics on one hand, and counter-terrorism measures, on the other, since 2001. The terrorist attacks of September 11, 2001 in the United States marked a turning point in the understanding of terrorism within the international society (Beck 2002, 39). Although the motives behind terrorism and counter-terrorism are opposite, their effects in terms of security and risk are similar. The similarities and differences between these two activities will be discussed in terms of risk and security within the international society. Central to the issues of security and risk, is the concept of an international society. An international society ‘exists when a group of states, conscious of certain common interests and common values, form a society in the sense that they conceive themselves to be bound by a common set of rules in their relations with one anther, and share in the working of common institutions’ (Bull and Watson 1984, 1). These rules, norms and institutions which make up international society is the central focus...
Words: 2232 - Pages: 9
...Over-The-Counter Drug Abuse When most people think of drug abuse they associate it with illegal activities. They believe drug abuse only includes illegal substances and prescription medication. People feel since they are legal and easy to get, over the counter medications (OTC’s) are safe. When used as directed, OTC’s can be very effective and safe. However, excessive over use and abuse of (OTC’s) can be extremely dangerous and sometimes even deadly. The most oblivious danger of (OTC‘s) is their availability. The availability of OTC’s has made them the number one most abused drug in society today. Behaviors seen in drug abuse may include consumption of a medication for non-medical reasons, consuming dose amounts greater than directed, consuming excessive dosages or more frequently than directed as well as using a medication for longer periods of time than the label recommends. There are more than 100 million Americans who suffer from some form of chronic pain. With the bad economy and increasing healthcare cost today, so many Americans are using so many OTC medicines trying to save money. However, current use show over $180 billion is spent every year on OTC drugs in the US. Current trends show the most commonly abused OTC drugs are cough suppressants, cold/allergy medications, caffeine products, and nicotine replacements/smoking control medications. With more prescription drugs being made available in OTC form, the abuse of OTC drugs will only continue to...
Words: 444 - Pages: 2
...Systematic design of 3-bit counter with D flip-flops • Follow same procedure as before, building up the transition table • The difference is in the inputs needed for the flip-flops: the behaviour of a D flip-flop is much simpler: - Qn+1 = D - i.e. Q output after clock transition = D input at transition (which depends on the present states of the flip-flops) - value of Qn (before clock transition) has no direct effect - it is just a simple memory cell (latch) • There are no “don’t care” inputs for a simple counter, which leads to more complicated logic. State transition table for 3-bit counter with D flip-flops The ‘present state’ and ‘next state’ columns are the same as for the JKs present state label 0 1 2 3 4 5 6 7 C 0 0 0 0 1 1 1 1 B 0 0 1 1 0 0 1 1 A 0 1 0 1 0 1 0 1 label 1 2 3 4 5 6 7 0 next state C 0 0 0 1 1 1 1 0 B 0 1 1 0 0 1 1 0 A 1 0 1 0 1 0 1 0 inputs needed DC 0 0 0 1 1 1 1 0 DB 0 1 1 0 0 1 1 0 DA 1 0 1 0 1 0 1 0 Because the D flip-flops are simple memories, the inputs needed are identical to the next state. Simply copy the columns across — that’s all there is to it! K-maps for 3-bit counter with D flip-flops BA DC C 0 1 00 01 11 10 0 1 BA 0 1 1 0 0 1 There are no “don’t care” entries here. DC = A ⋅ C + B ⋅C + A ⋅ B ⋅C = ( A + B )⋅ C + A ⋅ B⋅ C = ( A⋅ B) ⋅C + ( A⋅ B) ⋅C = ( A⋅ B) ⊕ C DB = A⋅ B + A ⋅ B = A⊕ B DB C 0 1 00 01 11 10 0 0 BA 1 1 0 0 1 1 DA C 0 1 00 01 11 10 1 1 0 0 0 0 1 1 DA = A Compare expressions for JK and D flip-flops J=K A B C D 1 A...
Words: 671 - Pages: 3
...Analysis of New England Foundry In this analysis of New England Foundry we need to make a comparison with each of the models or layouts, the first combined counter with the new mentioned model with separated counters, for the determination of time saved with the new layout and then the amount that could be saved per hour with the same. For the layout with combined counter there is 2 servers with a single waiting line, the queuing model that is being used is the M/M/s, because of this queuing pattern consists of single phase and multiple servers. The arrival rate of 7 (4+3) per hour and service rate of 5per hour, which gives the average time in the system W=0.3922hours or 23.53minutes (refer to Excel) the time taken per trip is as follows: For maintenance people it will be 23.53+6 (walking time taken) =29.53minutes. For molding people 23.53+2= 25.53minutes. For the new layout with separate counters, Bob for the maintenance shop and Pete for pattern shop both of them follow M/M/1 model with single-server and single-waiting line. Bob providing for the maintenance people, serves 6per hour at an arrival rate of 4per hour, giving the average time in the system W=0.50hours or 30minutes(shown in A5) with the time taken for trip is 2minutes 30+2=32minutes, this is an increase of time, 2.47minutes compared with the other layout for maintenance dept. Pete serving the molding people, serves 7per hour at an arrival rate of 3per hour, giving the average time...
Words: 429 - Pages: 2
...1- Implement Asynchronous Counters Theory: 1. What makes a counter asynchronous? The counter is asynchronous because its clock is only applied to a single flip-flop. 2. What is the modulus or count range of the following counter? 16 cycles will count from 0-15 Planning: 3. What is the purpose of the ELVISmx Dig In instrument? display the output of the counter Test Procedure: 4. Record the observed values from Lab 5 Table 5-1. Record the state number, the value of QDQCQBQA, the hexadecimal and decimal values. StateNumber | DataLine 7 | DataLine 6 | DataLine 5 | DataLine 4 | Hexadecimal | Decimal | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 2 | 0 | 0 | 1 | 0 | 2 | 2 | 3 | 0 | 0 | 1 | 1 | 3 | 3 | 4 | 0 | 1 | 0 | 0 | 4 | 4 | 5 | 0 | 1 | 0 | 1 | 5 | 5 | 6 | 0 | 1 | 1 | 0 | 6 | 6 | 7 | 0 | 1 | 1 | 1 | 7 | 7 | 8 | 1 | 0 | 0 | 0 | 8 | 8 | 9 | 1 | 0 | 0 | 1 | 9 | 9 | 10 | 1 | 0 | 1 | 0 | A | 10 | 11 | 1 | 0 | 1 | 1 | B | 11 | 12 | 1 | 1 | 0 | 0 | C | 12 | 13 | 1 | 1 | 0 | 1 | D | 13 | 14 | 1 | 1 | 1 | 0 | E | 14 | 15 | 1 | 1 | 1 | 1 | F | 15 | | | | | | | | | | | | | | | ------------------------------------------------- Part 2- Implement Synchronous Counters Theory: 5. What makes a counter synchronous? Because its clock is applied to each of the flip-flops. 6. What is the purpose of the ~U/D control signal for the 74191 Synchronous Counter? when low, counts up, when...
Words: 591 - Pages: 3
...Lab 9. Counter design. 1. Objectives - Design of the synchronous finite state machine (FSM) with D-flip-flops and multiplexers - Verification of the circuit behavior with a CAD tool 2. Problem description Design the synchronous 4-bit counter which outputs follow the predetermined repeated sequence of states. The sequence of states represents the sequence of decimal digits of your ID number with the following exceptions: (1) digits which appear more than ones have to be deleted; (2) digit 9 has to be added at the end of the sequence if your ID has no 9. For example, for ID number 105123456 the second 1 and 5 are deleted and 9 is added at the end resulting in sequence 10523469. In the binary form the sequence is shown in Figure 1. The initial state is not critical. State 9 should be decoded to generate special signal SYNC shown in denominator in Figure 1. In the prelab: the circuit behavior has to be verified in OrCAD. The maximum clock frequency has to be calculated using timing specs of the flip-flops and multiplexers (logical gates) from datasheet. In the experiment: first, the functionality of the counter has to be tested with a pushbutton that controls the clock and a 7-segment LED display connected to the outputs. Finally, the counter sequence should be demonstrated with the logic analyzer synchronized with SYNC signal, 4inputs of the logic analyzer should be grouped into a bus. 3. Approaches Outputs of four D-flip-flops Q3Q2Q1Q0 serve as outputs of the counter. Next states...
Words: 1781 - Pages: 8
...Asynchronous Counter: 2 Muhammad Usman Arif 12/11/2013 1 12/11/2013 MODULUS OF A COUNTER: The modulus of a counter is the number of unique states that the counter will sequence through. The maximum possible number of states (maximum modulus) of a counter is 2n. Where n is the number of flip-flops in the counter. TRUNCATED SEQUENCES: Counters can also be designed that have a number of states in their sequence that is less than the maximum of 2n.the resulting sequence is called a truncated sequence. Muhammad Usman Arif 3 12/11/2013 ASYNCHRONOUS DECADE COUNTER: To obtain a truncated sequence, it is necessary to force the counter to recycle before going through all of its possible states. For example, the BCD decade counter must recycle back to the 0000 state after the 1001 state. One way to make the counter recycle after the count of nine (1001) is to decode count ten (1010) with a NAND gate and connect the output the clear (CLR) input. 4 Muhammad Usman Arif 12/11/2013 2 12/11/2013 ASYNCHRONOUS DECADE COUNTER: 5 Muhammad Usman Arif 12/11/2013 PARTIAL DECODING: Notice in the figure that only Q1 and Q3 are connected to the NAND gate inputs. This arrangement is an example of partial decoding; in which the two unique states (Q1 = 1 and Q3 =1 ) are sufficient to decode the count of ten because none of the other states (zero through nine) have both Q1 and Q3 HIGH at the same time. When the counter goes into...
Words: 492 - Pages: 2
...1(a) F(w,x,y,z) = wʹxʹyʹzʹ + wʹxʹyzʹ + wxʹyʹzʹ + wʹxyʹzʹ + wʹxyz + wʹxyzʹ + wxʹyzʹ | | | | | | | | | | | | | | | | Minimal sum of products form: F(w,x,y,z) = x’z’ + w’z’ + w’xy (b) F (w,x,y,z) = xz’ + w’z’ + w’xy (using Only NAND Gates) F F (c) (i) | | | | | | | | S (p,q,r) = p | | | | | | | | T (p,q,r) = pq’ + p’q = p XOR q | | | | | | | | U (p,q,r) = q’r + qr’ = p XOR r (ii) (d)(i) Multiplexer How it works: * A multiplexer is a combinational circuit which connects multiple input lines to a single output, allowing only a single selected input signal to be passed to the output line at a time. * An Input signal is selected to be passed to output based on selection code which is implemented as two select lines. Typical Inputs and Outputs: * Consider a 4 -to -1 Multiplexer, typical inputs include four input lines labelled C0, C1, C2 and C3, along with two select lines labelled S0 and S1. * Output include single output line labelled F. Labelled diagram of 4-to-1 Multiplexer: (ii) Jk Flip Flop How it works: * A JK flip-flop is a sequential circuit which has two inputs that are similar to that of an S-R flip-flop, however all possible combinations of input values are valid...
Words: 1667 - Pages: 7
...วงจรนับ (Counter) วงจรรีจีสเตอร์ (Register) 1. บทนำ วงจรนับและรีจีสเตอร์เป็นการประยุกต์เอา ฟลิปฟลอป มาใช้งาน วงจรนับเป็นวงจรที่เกิดจากการนำ ฟลิปฟลอปมาต่อรวมกันหลายตัว เพื่อทำหน้าที่นับจำนวน คล๊อก (Clock) หรือพัลซ์ (Pulse) ที่ป้อนเข้าทางอินพุต หรือบางที่อาจเรียกว่าวงจรหารความถี่ ส่วนรีจีสเตอร์ก็เช่นเดียวกันโดยจะประกอบด้วย ฟลิปฟลอปเป็นพื้นฐาน ใช้ทำหน้าที่เก็บข้อมูลก่อนนำไปประมวลผลและใช้เลื่อนข้อมูล ซึ่งเรียกว่า ชิฟรีจีสเตอร์ (Shift Register) ในบทนี้จะได้กล่าวถึงรายละเอียดต่อไป วงจรนับแบ่งได้เป็น 2 ชนิด ได้แก่ วงจรนับแบบไม่เข้าจังหวะ (Asynchronous) และวงจรนับแบบเข้าจังหวะ (Synchronous) 2. Asynchronous Counter (Ripple Counter) วงจรนับแบบไม่เข้าจังหวะ โดยพื้นฐานจะใช้ J-K Flip Flop มาต่อเรียงกันดังวงจรในรูปข้างล่าง สถานะเอาท์พุตของ ฟลิปฟลอปแต่ละตัว (ฟลิปฟลอป 1 ตัว จะแทนเลขฐานสองได้ 1 บิท) ขึ้นอยู่กับสถานะเอาท์พุตของฟลิปฟลอปตัวก่อนหน้า คือ ฟลิปฟลอปตัวแรกจะส่งสัญญาณ (Pulse ) จาก Q ไปกระตุ้น (Trigger) ที่ Clk ของฟลิปฟลอปตัวที่สอง และฟลิปฟลอปตัวที่สองจะส่งสัญญาณไปกระตุ้น (Trigger) ที่ Clk ของฟลิปฟลอปตัวที่สาม ไปเรื่อย ๆ ตามลำดับ การทำงานของวงจรแบบนี้มีลักษณะไหลเป็นระลอก จึงทำให้มีชื่ออีกอย่างหนึ่งว่า วงจรนับแบบริบเปิล (Ripple Counter) 3. Binary Counter Binary Counter เป็นวงจรบันเลขฐานสอง ตัวอย่างวงจรข้างล่างเรียกว่า วงจรนับเลขฐานสองแบบไม่เข้าจังหวะ (Asynchronous Binary Counter) ใช้ J-K ฟลิปฟลอป และ ฟลิปฟลอปทุกตัวต่อในอยู่ในสถานะ Toggle คือ ให้ J และ K เป็น "1" เพื่อเตรียมพร้อมที่จะให้ ฟลิปฟลอป เปลี่ยนสถานะเอาท์พุต เมื่อมีคล็อก (Clock) ชนิดขอบขาลง...
Words: 715 - Pages: 3
...this lady a digital camera from the display cabinet. She’s been waiting half an hour and then……” Alright Chris I can help you out for a little while…..” two hours later, Kyle exited the electronics department disheartened. That’s no way for a store manager to spend his afternoon. There’s got to be a logical way to solve this, thought Kyle. He walked back to his office and wrote down the facts as he knew them. 6. Store policy allows customers to check out other items at the electronics counter if they are making purchases in that department. {This makes sense especially if the customer wants to write a check for the entire purchase.} Sebenarnya pelanggan layak membuat pemeriksaan sebelum dan selepas membeli. Ini kerana pelanggan mempunyai hak untuk mendapatkan barang dan perkhidmatan yang terbaik. 7. Store clerks must monitor the locked cabinets and stay with a customer who wants to view an item from the cabinet. 8. Because of the size of the enclosed department, only two checkout counters will fit in electronics. 9. Moving the electronics department to the front of the store would not be wise because shoppers tend to pick up impulse items on their way to the center of the...
Words: 414 - Pages: 2
...The Counter-Reformation: Catholic Baroque vs. the ‘Other’ Baroque With every change of power or order in society, whether it is in business or government, there is always a change in structure. Buildings and signage are redesigned with the idea of a complete marketing makeover. The same can be said for the Catholic Counter-Reformation of the mid sixteenth and seventeenth centuries, after the successful Protestant Reformation of the early 1500s. Rome called forth a physical change of the Catholic Church in response, and years later, the Calvinist churches (the Dutch Reformed Church) in the Netherlands called for a complete physical change of their structure as well. As a direct response to the Protestant movement that had turned successful, the Catholic Church met three times over nearly twenty years from 1545 until 1563 in what was called the Council of Trent. The Church decided to elicit an emotional response from current Catholics, as well as Catholics turned Protestants, with the hope of rejuvenating the foundations and population of the Church. Pope Paul III helped the council to redefine Catholic doctrine, as well as redefining the role of the clergy, which was deemed essential to the Church’s system of faith. During the sporadic meetings of the council, Pope Paul III commissioned artists and architects to create paintings and redesign buildings that would remind Catholics of the grandeur of their faith. The outcome needed by the Church was for its...
Words: 657 - Pages: 3