Abortion Pro-Life Free Essays

Abortion My conservative view on abortion highlights my views on life and how I believe that life starts at conception. Many people believe that it should be the woman’s right to decide what happens with her body but I disagree. Different news shows and newspapers broadcast their beliefs differently based on their political views. We will write a custom essay sample on Abortion Pro-Life or any similar topic only for you Order Now States are divided because they can’t seem to quite agree on this subject. Unborn babies have a fundamental right from the moment they are conceived to live their lives just like any other. They are innocent human beings who don’t have a voice to speak their opinion and need responsible parents to speak for them and make good decisions for their future. Liberals would state that a women’s right to her body is her choice she should get to decide whether or not she gets to keep it. Conservatives would call the Liberals liars and state that the only reason that they want to abort is because they have no necessary need for a baby. They should have thought about that before they went baby-making in the first place. Conservatives like Kanwaljeet J. S. Anand, a professor of Pediatrics, Neurobiology, and Anesthesiology believe that fetuses can feel pain if they are 20 or more weeks from the moment of gestation. She believes it to be excruciating pain. The bible’s sixth commandment also says that killing is a sin. Abortion involves killing a human being and defies a commandment from God. Liberals like Stuart W. G. Derbyshire, a PhD Senior Lecturer at the University of Birmingham states that fetuses don’t feel anything until they are born and surrounded by the real world. They think fetuses are not human beings. A fetus is considered to be human only when they are born. They argue that abortion is not killing another human being; it is simply terminating a pregnancy. Nobody can prove that personhood starts at conception. Liberals aren’t religious so they argue that the anti-abortion position is usually a religious position which threatens the separation of church and state. Religious beliefs are not to influence law in the United States. Conservatives say that the oath that doctors take when they become doctors forbids abortions when practicing medicine. An oath written by Luis Lasagna also forbids abortion in his line â€Å"Above all, I must not play God. † If religious beliefs are not to influence law then there should not be the use of God’s name in the Pledge of Allegiance or on the nation’s currency. The fact that religion is implemented in our society shows that we are a nation that is religious and relies on God. Therefore, abortions should be illegal. People that are pro-abortion would argue that abortions are safer than â€Å"back alley† abortions and reduce the number of deaths of mothers from 13 for every 100,000 during natural birth to less than 1 for every 100,000. A 1993 investigation found that a woman that has had 2 abortions has the same amount of chances of fertility as a woman that has had two natural births. Women should use contraceptives if they don’t want to birth a child, not abortions. A Center for Disease Control and Prevention found that 19-25% of women who received abortions had previously had one or more abortions. If abortion weren’t an option, women would learn how to be more careful with their bodies. Women say they have to abort because they do not have contraceptives available to them. They need a doctor’s prescription to have access to most birth control methods, like the pill, the patch, or the shot. Half of all large insurance companies do not cover the cost of birth control and only a third covers the birth control pill. In the year 2009, researchers have found that over 17 million women are without insurance. Women who abort are more prone to psychological diseases and damages. Studies show that women who aborted are 154% more likely to commit suicide than women who carried to term. Abortions also have a negative psychological effect on men. Men who’s partners have had abortions or forced them to feel regret, sadness, and go through depression. There are over two million couples that can’t have kids in the United States and there is a limited supply of kids available to adopt. There are only about 134,000 babies accessible to adopt as of June 2002. There would be more happy couples and more happy children in the world if they hadn’t been aborted. Just imagine if the world’s most famous athletes and scientists had been aborted because their mother’s didn’t want them. It should not be the mother’s decision on whether or not she gets to keep the baby. Even if there are licensed abortion physician doctors that perform those types of procedures, they are not supposed to call themselves doctors if they are taking away a humans life. There are about 1,800 licensed doctors that perform these horrendous acts. While selective abortion does give couples the option to choose not to birth babies with severe and life threatening conditions, it is based entirely on overt discrimination. The most famous people are people that were born with life threatening conditions much like the smartest guy on earth, Steven Hawking. There is an law called the Americans with Disabilities Act of 1990 that protects those people that need their civil rights protected for them to lead fulfilling lives. Abortion is an instrument of genocide especially for African Americans. African American women are 4. 5 times more likely to abort than white women. 1,876 African American babies are aborted every day. Abortion increases the likelihood that women will develop breast cancer. It interrupts the breast milking process and leaves those cells to just sit there. Tulare County alone has the most teen pregnancies and abortions. If teens did not abort so many children and respected themselves there would be more doctors and positions filled. There would be more high school graduates and more educated people to do higher end jobs. Minimum wage would be left to the high school students, while all the adults had higher end jobs. The unemployment rate would severely decrease and the unemployment claims would also decrease which would leave the state to spend more money on education and schools. The nation would be thriving with intelligent young adults and the world’s problems would get fixed much sooner like the deficit and all the money that comes out of the working class to pay for welfare. Works Cited http://abortion. procon. org/ http://www. dividedstates. com/abortion/ 12 December 2012 How to cite Abortion Pro-Life, Essay examples Abortion Pro-Life Free Essays Abortion: Pro-Life â€Å"Abortion is the termination of a pregnancy after, accompanied by, resulting in, or closely followed by the death of the embryo or fetus† (Lowenstein). Abortion is and always has been a very controversial issue. The above definition explains why the debate of abortion is so debatable. We will write a custom essay sample on Abortion: Pro-Life or any similar topic only for you Order Now A much asked question is whether or not the unborn child is considered human or not human. Since I am pro-life, I consider the unborn to be human, not just an embryo. I believe abortion should be illegal because it harm’s the pregnant woman’s body, it is against some religions.There are other options besides abortions available, and I believe that abortion is the murder of a human being. Abortion should be illegal to protect the unborn fetus; however, the mother’s health is also a major concern. One reason abortion should be illegal is because it is very dangerous for the woman getting the abortion. Approximately 1. 6 million women get abortions each year; out of those women getting an abortion there is about one death for every 250,000 abortions (Lowenstein). One negative aspect that comes out of an abortion is psychological side effects.It is said that the women can feel the babies dying inside them as they get an abortions. This major psychological side effect is called post-abortion syndrome. According to Felicia Lowenstein, Frequently after an abortion women suffer from a range of mental and psychological problems such as recurrent dreams of the abortion experience, avoidance of emotional attachment, relationship problems, sleep disturbances, guilt about surviving, memory impairments, hostile outbursts, suicidal thoughts or actions, depressions, and substance abuse. In an article titled â€Å"Complications You Can Have With Your Abortion† abortion causes many other dangerous side effects: bladder injury, bowel injury, increased risk of breast cancer, ectopic (tubal) pregnancy (pregnancy outside of the uterus), infection, laceration of the cervix (causes you to have a fifty/fifty chance of having a miscarriage your next pregnancy), failed abortion (failure to abort the child younger than six weeks is relatively common and causes the pregnancy to go on with the dangers of a normal abortion), hemorrhage, hepatitis, fever, rapid bleeding, and sterility.Abortion also has effects on future pregnancies. An abortion might also cause future problems such as bleeding in the first three months of future pregnancies, an unlikely chance of a normal delivery in the future delivery, a newborn will be more likely to die in the first few months of their first year of life, next baby may have a low birth weight, and a future baby will be more likely to be premature. Another major argument against abortion is the fact that it is against most religions.In the Bible in Psalm 139, David states that he acknowledges that God is omniscient and knows his thoughts at all times and that God was aware of his thoughts even before he was born (Anderson). The author also states that David also speaks of God’s relationship with David while he was growing and developing before birth. Anderson says that God knew David â€Å"even when he was in the womb† and he also refers to God as the â€Å"Master Craftsman† and praised him and said God did wonderfully creating David. Imagine how God feels.From what the Bible states God knows every child even when they are in the womb. So that means that every one of the 1. 6 million abortions that happen a year, God knows every single one of those unborn children. Taking the life of one of God’s children is wrong. Another strong argument against abortion is that there are other options available other than getting an abortion. One option for a woman is to put the baby up for adoption. This is an advantage for a number of reasons. One reason is that a woman could still be free to pursue her goals and dreams that she had before her pregnancy.A woman will not have to care for a baby before she is ready, and she also wouldn’t have the financial burden that a baby comes with. A woman will not have to worry about finding a babysitter or missing out on the fun with her friends and being tied down with a child. Instead of thinking of how the baby painfully died one can think of the child being loved by a mommy and daddy. Adoption is an option because the child’s mother will have precious memories of your baby’s face, fingers, toes, eyes and smile.She will also know that she gave the greatest gift of all to a couple who have obviously wanted a child to love and care for (Abortion Facts). This is good, too, because not only would a child’s life be saved instead of tragically being killed but a couple who has been wanting their own a child to love and care for would have their dreams fulfilled. The final argument I have against abortion is the fact that the unborn child is, in fact, human. I believe that since the child inside the mother’s womb is human that abortion is murder.The baby’s heartbeat in the mother’s womb starts beating after the twenty-first day of conception. Kerby Anderson stated that if there was one set of criteria to define death the same could define life. He said that death was defined as the cessation of the heartbeat. So does that mean that since death is defined †as the cessation of a heartbeat† that life can be defined as the onset of a heartbeat? Kerby Anderson also stated that â€Å"The heart is formed by the 18th day in the womb. If heartbeat was used to define life, then nearly all abortions would be outlawed. The baby also has been proven to have brainwaves by the forty to forty-third day after conception, and since death is defined by the cessation of brainwaves life should also be defined the same way (Anderson). Abortion is a procedure that the mother of the child chooses to undergo; the child does not choose to have his or her life terminated. I believe that every mother who chooses to get an abortion is intentionally killing a human being; and therefore, abortion is murder of the unborn. If the unborn baby who is inside the womb of a mother is human, then abortion is the intentional killing of a human being.The reasons that I am against abortions is because it harms the woman receiving the abortion’s body, it is against some religions, there are other options available the mother could do, and the baby inside the womb is human. Although abortion is a topic that has been argued for many years, i t is still a topic that must be carefully considered. No unborn child deserves to be murdered; each child deserves to live, to make choices, to affect the world. Many alternatives exist for woman- since those women are given choices shouldn’t the unborn; humans also have the chance to make choices. How to cite Abortion: Pro-Life, Papers

How I Learned to Cook free essay sample

How I Learned to Cook I want to tell how I began to learn cooking, and how I succeeded in this. When I was a child, approximately eight, I wanted to make a present for my mother. She was working hard and came back home late. So, I decided to cook for her a kind of food named ravioli with cottage cheese. It, like other kinds of food, has its rules of preparation. I didnt care about them, and I did what I thought was correct. Its a funny story. Each time when I remember it I laugh. At the end, I had a bowl with a mixture of dough and cheese. But I didnt stop to have interest for cooking. Later, my grandmother was the person who taught me to cook. She is a good cook. I watched her and asked questions. It was easier to cook after I saw in person how its done. We will write a custom essay sample on How I Learned to Cook or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page I used the observation way for learning cooking. Then most of what I learned was Just by reading a cooking book and following recipes. After a while, I became good in following the recipes. Every time, I discovered something new. Then I tried to alter the recipes to coincide with my own taste. There were a lot of trials and errors, but it was interesting. With time, my cooking skills were progressing, and at the present I know to cook quickly and tastily. Finally, I understood that experience of doing something is the best way to reinforce learning.

The topic of nature in 17th Century poetry Essay Example

The topic of nature in 17th Century poetry Paper The topic of nature is present in a number of the poems of the seventeenth century writers John Milton and Andrew Marvell. Indeed, in Marvells The Garden and The Mower Against Gardens, nature is arguably the central theme, and in Miltons Paradise Lost, the natural world is referred to throughout. However, when one considers that it is essential to think about the historical context- politically, religiously- and the ideological leanings of the writers of the seventeenth century when looking at works from that era, the theme of nature is present in these works to serve as more than a tribute to nature itself; nature is used also to allude to various theological and political ideals present at the time. When thinking about the theme of nature in seventeenth century poetry, Andrew Marvells The Garden is arguably the first work to spring to mind, as the poem is essentially a detailed description of a garden, and the various natural wonders within. However, a closer reading of the poem reveals the various political, classical and religious messages hidden inside Marvells Garden. Indeed, the very subject of gardens and gardening was a contentious one in seventeenth century England; changing Gods landscape by gardening was seen by Puritans to be counter religious. We will write a custom essay sample on The topic of nature in 17th Century poetry specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on The topic of nature in 17th Century poetry specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on The topic of nature in 17th Century poetry specifically for you FOR ONLY $16.38 $13.9/page Hire Writer However, as gardening developed in the seventeenth century, so did the poetry surrounding it, and although Marvell himself sometimes criticised the practice of turning productive land into gardens, he wrote The Garden, a hortus poem, as a tribute to gardens. With this in mind, the poem has already given us a point to consider: what sort of garden was Marvell praising, and what does this garden represent? The first stanza alone contains enough imagery to make it clear that this garden is representing a number of political and religious ideas. The vanity of man, the desire to achieve the unachievable, is referred to in the very first line: How vainly men themselves amaze. Military, civic, and poetic ambition are represented by the palm, the oak, or bays, and there are clear connections here to the English revolution. There is the idea that people put themselves through much toil to win little recognition, when far more could be gained with no toil at all: And their incessant Labours see Crownd from some single Herb or Tree, Whose short and narrow verged shade Does prudently their Toyles upbraid; While all Flowrs and all Trees do close To weave the Garlands of repose. As Lawrence W. Hyman wrote, it is Marvells awareness of the futility of human passion and ambition that makes him forsake society for the solitude, innocence and beauty of nature1 . The second stanza reinforces this idea: Fair quiet, have I found thee here, / And innocence, thy sister dear? , and the superiority of the garden compared to the society Marvell lives in is made clear when he states that he has been unable to find the innocence and calm he seeks In busy companies of men. Here we have the notion of a return to Eden from a postlapsarian, vain world; the fact that the plants are scared adds to this. The senses are evoked, as is the concept of fulfillment and the fertility of nature, by the solitude of the garden being described as delicious. Marvell then compares the beauty of the garden to that of a woman, No white nor red was ever seen/ so amorous as this lovely green, red and white being colours of femininity. Suggestions of misogyny perhaps stem from this third stanza, in which Marvell also states that no female can compare to the garden, and there is the intimation that Marvell would indeed rather embrace a tree than a woman, Fair trees! Whereeer your bark I wound. The fact that Marvell never married (the woman claiming to be his widow was apparently his housekeeper)2, along with the imagery present in this stanza offer us an insight into his view of women. The concept of an almost romantic love of nature continues into the forth stanza. Marvell implies that love is destined to fade When we have run our passions heat, and points out, with a classical reference, that even the gods ultimately value the beauty of nature over that of women. The story of Apollo and Daphne, from Ovids Metamorphoses, in which the god Apollo pursued Daphne until she transformed herself into a laurel tree, is used, and there is also a reference to Pan and Syrinx, a similar classical story. Marvell suggests here that the gods were only ever interested in the plants, not the women3. The fifth stanza contains perhaps the most natural imagery in the entire poem, and returns to the concept of fertility and life-giving nature, of another Eden. The garden is feeding Marvell in the line Ripe apples drop about my head, and the verdant descriptions of the gardens other vegetation again evoke the senses. There is also the notion of carelessness and ease; the nectarines and peaches are reaching themselves into Marvells hand, he only stumbles on melons, and the only thing to fall upon in grass. We are then introduced to the concept of hortus mentis, or garden of the mind, when Marvell writes, Meanwhile the mind, from pleasure less, /Withdraws into its happiness; the mind has left the garden, and withdrawn into itself, such is the tranquility and simplicity offered by the garden. Here Marvell is following the neo-Platonic philosophy present at the time. Continuing on from this, Marvell writes that the garden has freed the soul from the confines of the body, Casting the bodys vest aside, /My soul into the boughs does glide. Again this suggests a return to Eden, a loss of mortality, and the soul is also given an almost angelic quality, Then whets and combs its silver wings. The end of the poem describes an actual return to Eden, and again contains a hint of misogyny. When Marvell states, Such was that happy garden-state, /While man there walked without a mate, he is describing the past, the Garden of Eden, rather than the garden he has so far been speaking about. He is also suggesting that man was better off without a mate; without women. The final line of the poem again praises the peace of the garden, and states that that peace could be found nowhere else in the world in which he lived. In both Marvells The Garden and The Mower Against Gardens, the primary terms in opposition are the same: the worlds of nature and men. However, whilst in The Garden, the garden is a place of leisure, solace and tranquility, The Mower Against Gardens presents the garden as a place of endless toil and struggle. The relationship between the two poems is more complex than the mere conflict suggested by their titles: although the terms of the argument are constant between them, the value given to them shifts; the status of labour, leisure, and nature is different in each. Arguably, another difference is the tone of the two poems. Whilst one seems heartfelt in its argument, the other is almost self mocking. The very first line of The Mower Against Gardens presents the opposed terms of the poems argument, Luxurious man, to bring his vice in use, /Did after him the world seduce. Here Marvell is stating that it is not mans practice of his vices that corrupts, it is rather his determination to distort the world to follow his vice, to alter nature to reflect himself. This provides both an insight into Marvells views on gardening, of which, as stated earlier, he was often critical, and a further insight into what kind of garden is being represented in The Garden; it is not a man made space with mown grass and pruned hedges, it is a natural, uncultivated place. Also, this argument is representative of a more common moral issue; the true danger of immorality lies not in its practice by an individual, but in its transmission to others. This transmission comes about through careful perversion of nature, this passage argues, and its effects are as the corrupt man desires, The pink grew then as double in his mind; nature is reflecting the tainted man. Whilst in the first movement of the poem there is a sense of straying from nature, of knowingly perverting the earth, in line 22 a different kind of corruption is introduced. The use of forbidden suggests not only a moral lapse; it implies law, concrete rules whose breaking deserves punishment from a higher authority than man, however sovereign man has become, or thinks he has become. Indeed, the use of sovereign here seems almost ironic. This passage of the poem suggests that not only has nature been altered by man, its very essence has also been corrupted, No plant now knew the stock from which it came; / He grafts upon the wild the tame. To make matters worse, this transgression, this loss of origin, is frivolous, and not even intended to be of any benefit to man, but to rather cause dispute. This implies that not even pleasure governs mans behavior, but novelty. There is also the idea that mans distortion has become a religious transgression with the entrance on his green seraglio. In conclusion, it is clear that in Andrew Marvells The Garden and The Mower Against Gardens, nature is used for far more than a description of nature itself. The conflicting viewpoints of both poems are presented through the use of nature, which is used to allude to various religious, social and, political ideas, and it is only when both poems are read in the context of the time in which they were written that we can recognize these ideas.

Reform in the Age of jackson essays

Reform in the Age of jackson essays From about 1825 until the outbreak of the civil war in 1861, the atmosphere in the nation was one of reform (Boardman, 122). There were five major reform movements present in 19th century America. There was the Utopianism/Communitarian Movement, which established an ideal society away from present politics. Educational reforms were important in the fact of creating taxes to support the public school system, higher education for adults, and mandatory education and attendance. The Temperance Movement preached of abstinence from alcohol and the Womans Rights Movement was to improve the life of women politically, socially, and economically. It also included the strive for womens suffrage rights. Humanitarianism was improving the lives of those less fortunate. This movement also included and was closely related to the Abolition Movement. A great deal of the spirit to reform could be credited to the Enlightenment period of the 18th century, which was still influential in America. More recent though, was the period of Romanticism, which emphasized the goodness of nature and human kind. To all this was added the democratic spirit of equality and the goal of Utilitarianism: the achievement of the greatest happiness for the greatest number (Boardman, 123). Secular communities arose in the mid 1800s. The goal of these communities was to establish a new social order in society. They were religious and secular colonies where the entire population of the community shared property and work. They used idealistics as their model rather than radical doctrines. The Harmony Society was originally established in 1805 in the county Butler, Pennsylvania. Later, in 1814, the society moved to Indiana, and then moved again to Economy, Pennsylvania in 1825. Robert Owen founded the Society of New New Harmony, Indiana in 1825. This colony was to be a self-sufficient community, which was to exist wi...

Answer the questions Case Study Example | Topics and Well Written Essays - 250 words - 1

Answer the questions - Case Study Example Failure to pay taxes by Bill is also essential to this lawsuit. Overstatement of net annual profits by Sam is also fraudulent. Failure to disclose true and fair view information of the restaurant’s net profits creates a fine for Sam. Despite, the accountant disclosing the information on overstatement Bill still goes ahead to complete the sale indicating intention of hiding the improprieties by Sam (Hall, 2012). Sam can claim to have disclosed all information on the annual net profit of the restaurant through the brochure. Sam goes ahead to disclose the unreported cash transactions to Bill. Therefore, Bill is well aware of the nature of business and unpaid taxes. Bill goes ahead to accept and completes the sale. Making a net profit each year of a little less than $25,000 cannot be a basis to justify a breach of contract (Hall, 2012) Sam is liable for a fine for failure to report all transactions to IFS, which is fraudulent. Sam claims on breach of contract is invalid as he is well aware of the state of the restaurant dealings and attempts to cover the fraud (Hall,

Effects of Training and Development on Overall Organizational Research Paper

Effects of Training and Development on Overall Organizational Performance - Research Paper Example With employees’ development, an organization is able to retain them at their place of work for their own growth and for the growth of the organization for they will be able to fill new positions arising in the organization. In this paper, I will generally discuss training and development on overall organizational performance through work of HR management. I will also discuss how the human resource department seeks to improve the overall performance of its employees through training and development programs. The paper will deal mainly with the effects of training and development programs in improving employees’ performance and how it helps an organization to realize its goals by giving different perspectives from different authors and researchers. Training and development are essential to the success of all organizations. This is because; it ensures the ongoing managing of the performance of employees in organizations. Employee pieces of training not only set goals for t he employees but also monitors and motivates them in achieving the set goals. All human resource management should initiate training and development programs in their organizations so as to nurture professionals and a staff that is competent. It is vital because of the changes in economic and technological trends and the increase in the pace of modernization. All organizations need training and development so as to be able to grow faster with the changes. Training and development increase employees’ performance and it also increases the achievement of organizational goals. It is a fact that training and development of employees enhance eventual employee’s productivity and performance in an organization. Many organizations have occupied their staff in training and development programs so as to improve their performance. The performance of employees needs to be upgraded regularly. For an organization to meet its goals there is a need to instigate training, development, a nd employee evaluation programs. The best and most powerful tool in human resource training and development in e-learning. Online learning is very important because nowadays, everything is done technologically and all employees should be technologically literate. New technologies help in the improvement of an organizations performance. Even though there were cases whereby most employees were resistant to change, presently, they do embrace change. Due to this, most organizations are giving their employees training and development in their organizations for better performance. A research conducted by Rivera  found out that the human resource management is very confident and keen on the positive effects that training and development programs bring to their organizations (56). Many HR professionals interviewed during this research confirmed that the success and excellent performance of an organization highly rely on the constant training and development of its employees. The same rese arch revealed that many employees are happy with the training given to them and they also confirmed that it has improved their performance and it has increased their self-efficiency.

Microcontroller Embedded Memory Technology Information Technology Essay

Microcontroller Embedded Memory Technology Information Technology Essay A  microcontroller  is a small computer on a single  integrated circuit  containing a processor core, memory, and programmable  input/output  peripherals. Program memory in the form of  NOR flash  or  OTP ROM  is also often included on chip, as well as a typically small amount of  RAM. Microcontrollers are designed for embedded applications, in contrast to the  microprocessors  used inpersonal computers  or other general purpose applications. http://upload.wikimedia.org/wikipedia/commons/thumb/c/c7/153056995_5ef8b01016_o.jpg/230px-153056995_5ef8b01016_o.jpg Microcontrollers are used in automatically controlled products and devices, such as automobile engine control systems, implantable medical devices, remote controls, office machines, appliances, power tools, and toys. By reducing the size and cost compared to a design that uses a separate microprocessor, memory, and input/output devices, microcontrollers make it economical to digitally control even more devices and processes. Mixed signal microcontrollers are common, integrating analog components needed to control non-digital electronic systems. Some microcontrollers may use four-bit words and operate at  clock rate  frequencies as low as 4  kHz, for low power consumption (milliwatts or microwatts). They will generally have the ability to retain functionality while waiting for an event such as a button press or other interrupt; power consumption while sleeping (CPU clock and most peripherals off) may be just nanowatts, making many of them well suited for long lasting battery applications. Other microcontrollers may serve performance-critical roles, where they may need to act more like a  digital signal processor(DSP), with higher clock speeds and power consumption. Embedded design A microcontroller can be considered a self-contained system with a processor, memory and peripherals and can be used as an  embedded system.[1]  The majority of microcontrollers in use today are embedded in other machinery, such as automobiles, telephones, appliances, and peripherals for computer systems. These are called  embedded systems. While some embedded systems are very sophisticated, many have minimal requirements for memory and program length, with no operating system, and low software complexity. Typical input and output devices include switches,  relays,  solenoids,  LEDs, small or custom  LCD  displays, radio frequency devices, and sensors for data such as temperature, humidity, light level etc. Embedded systems usually have no keyboard, screen, disks, printers, or other recognizable I/O devices of a  personal computer, and may lack human interaction devices of any kind. Interrupts Microcontrollers must provide  real time  (predictable, though not necessarily fast) response to events in the embedded system they are controlling. When certain events occur, an  interruptsystem can signal the processor to suspend processing the current instruction sequence and to begin an  interrupt service routine  (ISR, or interrupt handler). The ISR will perform any processing required based on the source of the interrupt before returning to the original instruction sequence. Possible interrupt sources are device dependent, and often include events such as an internal timer overflow, completing an analog to digital conversion, a logic level change on an input such as from a button being pressed, and data received on a communication link. Where power consumption is important as in battery operated devices, interrupts may also wake a microcontroller from a low power sleep state where the processor is halted until required to do something by a peripheral event. Programs Microcontroller programs must fit in the available on-chip program memory, since it would be costly to provide a system with external, expandable, memory. Compilers and assemblers are used to convert high-level language and assembler language codes into a compact  machine code  for storage in the microcontrollers memory. Depending on the device, the program memory may be permanent, read-only memory that can only be programmed at the factory, or program memory may be field-alterable flash or erasable read-only memory. Other microcontroller features Microcontrollers usually contain from several to dozens of general purpose input/output pins (GPIO). GPIO pins are software configurable to either an input or an output state. When GPIO pins are configured to an input state, they are often used to read sensors or external signals. Configured to the output state, GPIO pins can drive external devices such as LEDs or motors. Many embedded systems need to read sensors that produce analog signals. This is the purpose of the  analog-to-digital converter  (ADC). Since processors are built to interpret and process digital data, i.e. 1s and 0s, they are not able to do anything with the analog signals that may be sent to it by a device. So the analog to digital converter is used to convert the incoming data into a form that the processor can recognize. A less common feature on some microcontrollers is a  digital-to-analog converter  (DAC) that allows the processor to output analog signals or voltage levels. In addition to the converters, many embedded microprocessors include a variety of timers as well. One of the most common types of timers is the  Programmable Interval Timer  (PIT). A PIT may either count down from some value to zero, or up to the capacity of the count register, overflowing to zero. Once it reaches zero, it sends an interrupt to the processor indicating that it has finished counting. This is useful for devices such as thermostats, which periodically test the temperature around them to see if they need to turn the air conditioner on, the heater on, etc. Time Processing Unit  (TPU) is a sophisticated timer. In addition to counting down, the TPU can detect input events, generate output events, and perform other useful operations. A dedicated  Pulse Width Modulation  (PWM) block makes it possible for the CPU to control  power converters,  resistive  loads,  motors, etc., without using lots of CPU resources in tight timerloops. Universal Asynchronous Receiver/Transmitter  (UART) block makes it possible to receive and transmit data over a serial line with very little load on the CPU. Dedicated on-chip hardware also often includes capabilities to communicate with other devices (chips) in digital formats such as  I2C  and  Serial Peripheral Interface  (SPI). Higher integration In contrast to general-purpose CPUs, micro-controllers may not implement an external address or data bus as they integrate RAM and non-volatile memory on the same chip as the CPU. Using fewer pins, the chip can be placed in a much smaller, cheaper package. Integrating the memory and other peripherals on a single chip and testing them as a unit increases the cost of that chip, but often results in decreased net cost of the embedded system as a whole. Even if the cost of a CPU that has integrated peripherals is slightly more than the cost of a CPU and external peripherals, having fewer chips typically allows a smaller and cheaper circuit board, and reduces the labor required to assemble and test the circuit board. A micro-controller is a single  integrated circuit, commonly with the following features: central processing unit   ranging from small and simple 4-bit  processors to complex 32- or 64-bit processors discrete input and output bits, allowing control or detection of the logic state of an individual package pin serial  input/output  such as  serial ports  (UARTs) other  serial communications  interfaces  like  I ²C,  Serial Peripheral Interface  and  Controller Area Network  for system interconnect peripherals  such as  timers, event counters,  PWM generators, and  watchdog volatile memory (RAM) for data storage ROM,  EPROM,  EEPROM  or  Flash memory  for  program  and operating parameter storage clock generator   often an oscillator for a quartz timing crystal, resonator or  RC circuit many include analog-to-digital converters in-circuit programming and debugging support This integration drastically reduces the number of chips and the amount of wiring and  circuit board  space that would be needed to produce equivalent systems using separate chips. Furthermore, and on low pin count devices in particular, each pin may interface to several internal peripherals, with the pin function selected by software. This allows a part to be used in a wider variety of applications than if pins had dedicated functions. Micro-controllers have proved to be highly popular in  embedded systems  since their introduction in the 1970s. Some microcontrollers use a  Harvard architecture: separate memory buses for instructions and data, allowing accesses to take place concurrently. Where a Harvard architecture is used, instruction words for the processor may be a different bit size than the length of internal memory and registers; for example: 12-bit instructions used with 8-bit data registers. The decision of which peripheral to integrate is often difficult. The microcontroller vendors often trade operating frequencies and system design flexibility against time-to-market requirements from their customers and overall lower system cost. Manufacturers have to balance the need to minimize the chip size against additional functionality. Microcontroller architectures vary widely. Some designs include general-purpose microprocessor cores, with one or more ROM, RAM, or I/O functions integrated onto the package. Other designs are purpose built for control applications. A micro-controller instruction set usually has many instructions intended for bit-wise operations to make control programs more compact.[2]For example, a general purpose processor might require several instructions to test a bit in a register and branch if the bit is set, where a micro-controller could have a single instruction to provide that commonly-required function. Microcontrollers typically do not have a  math coprocessor, so  floating point  arithmetic is performed by software. Volumes About 55% of all  CPUs  sold in the world are  8-bit  microcontrollers and microprocessors. According to Semico, over four billion 8-bit microcontrollers were sold in 2006.[3] A typical home in a developed country is likely to have only four general-purpose microprocessors but around three dozen microcontrollers. A typical mid-range automobile has as many as 30 or more microcontrollers. They can also be found in many electrical devices such as washing machines, microwave ovens, and telephones. http://upload.wikimedia.org/wikipedia/commons/thumb/1/18/PIC18F8720.jpg/220px-PIC18F8720.jpg A  PIC  18F8720  microcontroller  in an 80-pin  TQFP  package. Manufacturers have often produced special versions of their microcontrollers in order to help the hardware and  software development  of the target system. Originally these included  EPROM  versions that have a window on the top of the device through which program memory can be erased byultraviolet  light, ready for reprogramming after a programming (burn) and test cycle. Since 1998, EPROM versions are rare and have been replaced by  EEPROM  and  flash, which are easier to use (can be erased electronically) and cheaper to manufacture. Other versions may be available where the  ROM  is accessed as an external device rather than as internal memory, however these are becoming increasingly rare due to the widespread availability of cheap microcontroller programmers. The use of field-programmable devices on a microcontroller may allow field update of the  firmware  or permit late factory revisions to products that have been assembled but not yet shipped. Programmable memory also reduces the lead time required for deployment of a new product. Where hundreds of thousands of identical devices are required, using parts programmed at the time of manufacture can be an economical option. These mask programmed parts have the program laid down in the same way as the logic of the chip, at the same time. Programming environments Microcontrollers were originally programmed only in  assembly language, but various  high-level programming languages  are now also in common use to target microcontrollers. These languages are either designed specially for the purpose, or versions of general purpose languages such as the  C programming language.  Compilers  for general purpose languages will typically have some restrictions as well as enhancements to better support the unique characteristics of microcontrollers. Some microcontrollers have environments to aid developing certain types of applications. Microcontroller vendors often make tools freely available to make it easier to adopt their hardware. Many microcontrollers are so quirky that they effectively require their own non-standard dialects of C, such as  SDCC for the 8051, which prevent using standard tools (such as code libraries or static analysis tools) even for code unrelated to hardware features. Interpreters are often used to hide such low level quirks. Interpreter  firmware is also available for some microcontrollers. For example,  BASIC  on the early microcontrollers  Intel  8052[4]; BASIC and  FORTH  on the  Zilog Z8[5]  as well as some modern devices. Typically these interpreters support  interactive programming. Simulators  are available for some microcontrollers, such as in Microchips  MPLAB  environment. These allow a developer to analyze what the behavior of the microcontroller and their program should be if they were using the actual part. A simulator will show the internal processor state and also that of the outputs, as well as allowing input signals to be generated. While on the one hand most simulators will be limited from being unable to simulate much other hardware in a system, they can exercise conditions that may otherwise be hard to reproduce at will in the physical implementation, and can be the quickest way to debug and analyze problems. Recent microcontrollers are often integrated with on-chip  debug  circuitry that when accessed by an  in-circuit emulator  via  JTAG, allow debugging of the firmware with a  debugger. Types of microcontrollers : Freescale 68HC11  (8-bit) Intel 8051 ARM  processors (from many vendors) using  ARM7  or Cortex-M3 cores are generally microcontrollers STMicroelectronics  STM8  (8-bit),  ST10  (16-bit) and  STM32  (32-bit) Atmel  AVR  (8-bit),  AVR32  (32-bit), and  AT91SAM  (32-bit) Freescale  ColdFire  (32-bit) and  S08  (8-bit) Hitachi H8,  Hitachi SuperH  (32-bit) Hyperstone  E1/E2 (32-bit, First full integration of  RISC  and  DSP  on one processor core [1996]  [1]) MIPS  (32-bit PIC32) NEC V850  (32-bit) PIC  (8-bit PIC16, PIC18, 16-bit dsPIC33 / PIC24) PowerPC  ISE PSoC (Programmable System-on-Chip) Rabbit 2000  (8-bit) Texas Instruments Microcontrollers  MSP430  (16-bit), C2000 (32-bit), and Stellaris (32-bit) Toshiba TLCS-870  (8-bit/16-bit) Zilog eZ8  (16-bit),  eZ80  (8-bit) and many others, some of which are used in very narrow range of applications or are more like applications processors than microcontrollers. The microcontroller market is extremely fragmented, with numerous vendors, technologies, and markets. Note that many vendors sell (or have sold) multiple architectures. Interrupt latency In contrast to general-purpose computers, microcontrollers used in embedded systems often seek to optimize  interrupt latency  over instruction throughput. Issues include both reducing the latency, and making it be more predictable (to support real-time control). When an electronic device causes an interrupt, the intermediate results (registers) have to be saved before the software responsible for handling the interrupt can run. They must also be restored after that software is finished. If there are more registers, this saving and restoring process takes more time, increasing the latency. Ways to reduce such context/restore latency include having relatively few registers in their central processing units (undesirable because it slows down most non-interrupt processing substantially), or at least having the hardware not save them all (this fails if the software then needs to compensate by saving the rest manually). Another technique involves spending silicon gates on shadow registers: one or more duplicate registers used only by the interrupt software, perhaps supporting a dedicated stack. Other factors affecting interrupt latency include: Cycles needed to complete current CPU activities. To minimize those costs, microcontrollers tend to have short pipelines (often three instructions or less), small write buffers, and ensure that longer instructions are continuable or restartable.  RISC  design principles ensure that most instructions take the same number of cycles, helping avoid the need for most such continuation/restart logic. The length of any  critical section  that needs to be interrupted. Entry to a critical section restricts concurrent data structure access. When a data structure must be accessed by an interrupt handler, the critical section must block that interrupt. Accordingly, interrupt latency is increased by however long that interrupt is blocked. When there are hard external constraints on system latency, developers often need tools to measure interrupt latencies and track down which critical sections cause slowdowns. One common technique just blocks all interrupts for the duration of the critical section. This is easy to implement, but sometimes critical sections get uncomfortably long. A more complex technique just blocks the interrupts that may trigger access to that data structure. This often based on interrupt priorities, which tend to not correspond well to the relevant system data structures. Accordingly, this technique is used mostly in very constrained environments. Processors may have hardware support for some critical sections. Examples include supporting atomic access to bits or bytes within a word, or other atomic access primitives like theLDREX/STREX  exclusive access primitives introduced in the  ARMv6  architecture. Interrupt nesting. Some microcontrollers allow higher priority interrupts to interrupt lower priority ones. This allows software to manage latency by giving time-critical interrupts higher priority (and thus lower and more predictable latency) than less-critical ones. Trigger rate. When interrupts occur back-to-back, microcontrollers may avoid an extra context save/restore cycle by a form of  tail call  optimization. Lower end microcontrollers tend to support fewer interrupt latency controls than higher end ones. History The first single-chip microprocessor was the 4-bit  Intel 4004  released in 1971. With the  Intel 8008  and more capable microprocessors available over the next several years. These however all required external chip(s) to implement a working system, raising total system cost, and making it impossible to economically computerize appliances. The first computer system on a chip optimized for control applications was the  Intel 8048  released in 1975,[citation   with both  RAM  and  ROM  on the same chip. This chip would find its way into over one billion PC keyboards, and other numerous applications. At this time Intels President, Luke J. Valenter, stated that the (Microcontroller) was one of the most successful in the companies history, and expanded the divisions budget over 25%. Most microcontrollers at this time had two variants. One had an erasable  EPROM  program memory, which was significantly more expensive than the  PROM  variant which was only programmable once. In 1993, the introduction of  EEPROM  memory allowed microcontrollers (beginning with the Microchip  PIC16x84)  [2][citation needed]) to be electrically erased quickly without an expensive package as required for  EPROM, allowing both rapid prototyping, and  In System Programming. The same year, Atmel introduced the first microcontroller using  Flash memory.[6] Other companies rapidly followed suit, with both memory types. Cost has plummeted over time, with the cheapest 8-bit microcontrollers being available for under $0.25 in quantity (thousands) in 2009,[citation needed]  and some 32-bit microcontrollers around $1 for similar quantities. Nowadays microcontrollers are low cost and readily available for hobbyists, with large online communities around certain processors. In the future,  MRAM  could potentially be used in microcontrollers as it has infinite endurance and its incremental semiconductor wafer process cost is relatively low. Microcontroller embedded memory technology Since the emergence of microcontrollers, many different memory technologies have been used. Almost all microcontrollers have at least two different kinds of memory, a non-volatile memory for storing firmware and a read-write memory for temporary data. Data From the earliest microcontrollers to today, six-transistor SRAM is almost always used as the read/write working memory, with a few more transistors per bit used in the  register file.  MRAMcould potentially replace it as it is 4-10 times denser which would make it more cost effective. In addition to the SRAM, some microcontrollers also have internal EEPROM for data storage; and even ones that do not have any (or not enough) are often connected to external serial EEPROM chip (such as the  BASIC Stamp) or external serial flash memory chip. A few recent microcontrollers beginning in 2003 have self-programmable flash memory[6]. Firmware The earliest microcontrollers used hard-wired or mask ROM to store firmware. Later microcontrollers (such as the early versions of the  Freescale 68HC11  and early  PIC microcontrollers) had quartz windows that allowed ultraviolet light in to erase the  EPROM. The Microchip  PIC16C84, introduced in 1993,[7]  was the first microcontroller to use  EEPROM  to store firmware. Also in 1993, Atmel introduced the first microcontroller using  NOR Flash memory  to store firmware.[6] PSoC  microcontrollers, introduced in 2002, store firmware in  SONOS  flash memory. MRAM  could potentially be used to store firmware.