...Chapter 6 - Exercises 1. [10 points] What is memory mapped I/O? An I/O scheme in which portions of address space are assigned to I/O devices, and reads and writes to those addresses are interpreted as commands to the I/O device 2. [10 points] Why is DMA an improvement over CPU programmed I/O? When CPU programmed I/O is used the CPU is usually fully occupied for the entire duration of the read or write operation and is unavailable to perform other work. With DMA the CPU initiates the transfer, does other operations while the transfer is in progress, and receives an interrupt form the DMA controller when the operation is complete. This frees up the CPU for other tasks. 3. [10 points] When would DMA transfer be a poor choice? When the amount of data transferred between memory and the I\O device is small. In this case the work to set it up would be more than the benefits of having it. 4. [15 points] Mention two advantages and disadvantages for using a single bus as a shared communication link between memory, processor and I/O devices. Advantages: versatility and low cost Disadvantages: communication bottleneck 5. [15 points] What is the average time to read or write a 512-byte sector for a typical disk rotating at 7200 RPM? The advertised average seek time is 8ms, the transfer rate is 20MB/sec, and the controller overhead is 2ms. Assume that the disk is idle so that there is no waiting time. -8 + (.5*60*1000/7200) + (512/20*2^20) * 1000...
Words: 460 - Pages: 2
...Most I/O devices interface to the CPU in a fashion quite similar to memory. Indeed, many devices appear to the CPU as though they were memory devices. To output data to the outside world the CPU simply stores data into a "memory" location and the data magically appears on some connectors external to the computer. Similarly, to input data from some external device, the CPU simply transfers data from a "memory" location into the CPU; this "memory" location holds the value found on the pins of some external connector. An output port is a device that looks like a memory cell to the computer but contains connections to the outside world. An I/O port typically uses a latch rather than a flip-flop to implement the memory cell. When the CPU writes to the address associated with the latch, the latch device captures the data and makes it available on a set of wires external to the CPU and memory system (see Figure 7.1). Note that output ports can be write-only, or read/write. The port in Figure 7.1, for example, is a write-only port. Since the outputs on the latch do not loop back to the CPU's data bus, the CPU cannot read the data the latch contains. Both the address decode and write control lines must be active for the latch to operate; when reading from the latch's address the decode line is active, but the write control line is not. Figure 7.1 A Typical Output Port Figure 7.2 shows how to create a read/write input/output port. The data written to the output port loops...
Words: 3087 - Pages: 13
...connection of smell and taste. Different fluids and water are chemical substances that dissolve in the mouth that is a stimuli of taste. “There are four basic descriptions that stimuli taste, they are the following, bitter, salty, sour and sweet. These sensations can be combined to stimulate different types of stimulation of taste,” (Bartoshuk, L. M., & Beauchamp, G. K.) (1994), Chemical senses. Examples would consist of salt and vinegar potato chips, sweet and sour chicken, and other different combinations. Taste buds that are located on the tongue are called receptors, there are thousands of tiny bumps (taste buds) all around the tongue that are called papillae. Within each papilla there are many taste buds and information is conveyed by nerves, then to the thalamus and finally to the area of the cortex. “For smell, in humans the olfactory receptors work together to detect different types of smells, there are over 400 types of different sensors in the receptors of the olfactory,” (Monell chemical senses center; extensive variability in olfactory receptors influences human odor perception. (2013). The stimuli chemical substances are in the atmosphere, which as in a result the olfactory receptors are simulated by these substances. The receptors are located in the upper portions of the nasal passages. The olfactory nerve is formed when neurons bundle up together by the receptors. At the base of the brain the nerve travels to the olfactory bulb. How do smell and taste affect...
Words: 1243 - Pages: 5
...make a person assume a specific way about the area. The way something smells can make a person decide, without any other information, whether or not they like a product or service. The way the senses guide people in their decision making can either make them have conscious decisions or it can make them close-minded to the area around them. The three main functions of sensory information are: The sensory nerves gather information from the environment then sends that info to the spinal cord, which then speed the message to the brain. The brain then makes sense of that message and fires off a response. Motor neurons deliver the instructions from the brain to the rest of your body. The spinal cord, made of a bundle of nerves running up and down the spine, is similar to a superhighway, speeding messages to and from the brain at every second (The Brain, 2005). Information is passed from the sensory memory into short-term memory via the process of attention (the cognitive process of selectively concentrating on one aspect of the environment while ignoring other things), which effectively filters the stimuli to only those which are of interest at any given time (Sensory Memory). Sensory memory is an ultra-short-term memory and decays or degrades very quickly, typically in the region of 200 - 500 milliseconds (1/5 - 1/2 second) after the perception of an item, and certainly less than a second (although echoic memory is now thought to last a little longer, up to perhaps three or four...
Words: 834 - Pages: 4
...Phoenix Intro The senses of smell and taste are chemically based senses that are unique to the other senses in the way in which the brain interprets them. Unlike other senses which are perceived and categorized analytically, taste and smell both pass through the emotional response center of the brain on the way to their being stored as memories, evoking an emotional association to their formation as engrams. Consider the unlikely association between taste and smell and the emotional response that they can trigger; a chemical reaction that gives off a gaseous “odor”, completely quantifiable by scientific standards, can trigger a purely emotional, unquantifiable response. The question then becomes, how do smell and taste play on our emotions? How do Smell and Taste Effect Each Other? The senses of smell and taste are integrally linked, the ability to do one without the other is not possible with the way that the brain is wired. Physiologically speaking, the way that humans are “designed” or the way that we have evolved is that the nose and the mouth are located in proximity to each other. This means that as we taste a food we are also inhaling particles that create the aromas that are generated by that food, and the brain’s interpretation of the stimulus from the taste buds along with the olfactory sensors in the nose is simultaneous; the memory engrams that form based on the association are also closely associated. Consider, the smell of a lemon-pine cleaner as the brain...
Words: 1389 - Pages: 6
...through for our body to smell or taste something. So let’s explore this journey of smell and taste. Impacts of smell and taste When we taste something it is a process. Molecules enter the body in a solid or liquid form. They stimulate taste receptors on the tongue. There are five basic taste sensations: salty, sour, sweet, bitter, and umami. Umami is the latest addition. It is considered to be meaty, broth, or savory. Tasting begins with the tongue, which contains papillae. Papillae are divided into four areas: *Filiform are shaped like cones and are over the entire surface of the tongue making a rough appearance *Fungiform are shaped like mushrooms and are at the tip and sides of the tongue *Foliate are series of folds along the back of the tongue and on the sides *Circumvilliate are shaped like flat mounds surrounded by a trench and at the back of the tongue All of the papillae except the filiform papillae contain taste buds and the whole tongue contains about 10,000 taste buds (Bartoshuk, 1971). Our sense of smell comes from our olfactory system. This system has odorant molecules that flow over the olfactory mucosa. The mucosa contains over 350 types of olfactory receptor neurons. The olfactory system also acts as our “alarm system”. It helps us detect dangerous smells. And is very important to certain animals. Many animals are “macrosmatic” meaning that they have a keen sense of smell. It is important to their survival. The taste and smell sensation work together...
Words: 1304 - Pages: 6
...Perception, interpretation, and knowledge. Without ours senses we are nothing. We would not be able to Touch taste, feel, or smell. They are who we are. Perception is our sensory experience of the world around us and involves both the recognition of environmental stimuli and actions in response to these stimuli. http://www.studymode.com/subjects/. What we are experiencing at any given moment or our experience in life is what the inaccuracy of sensory information is based on. Knowledge is the key for believing in the accuracy or inaccuracy of sensory information. Knowledge informs decisions about what to believe and how to act. It also aides in making good decisions. More importantly, knowledge is the basis for right and wrong. Identify and describe at least three factors contributing to the accuracy of sensory data. One factor contributing to the accuracy of sensory data would be smell. Our sense of smell is very important. It can send us messages. If there is a fire you could smell it ahead of time and get others to safety. Your sense of smell could tell you messages about your own body if your body did not smell so pleasant, so that you can correct the problem. It can also aid you in cooking. Your sense of smell can give you a general idea of if the food is ready when you’re cooking or if it has cooked too long. It can also help you out when dating. When you smell good fragrances then you can give compliments which could eventually land you a companion. Another contributing factor...
Words: 779 - Pages: 4
...Chemical Senses Paper Psy/345 May 23. 2016 Chemical Senses Paper The Chemical senses, taste and smell, both provide information that can be determine survival. Taste will let us know whether or not we should eat something, based on the taste. Tastes are classified in five categories: sour, salty, bitter, unami, and sweet. these tastes are experienced through taste buds on the tongue. In the nose, when something is sniffed, molecules travel through the nose, and some activate responders on the olfactory epithelium. Olfaction, or the system of smelling, provides us with an alert system to dangerous odors, cues to orient ourselves, mark territory, a guide to specific places, animals, food, and in sexual reproduction for many species (pheromones). Our olfactory epithelium can be activated in as many as 10-100,000 different patterns, to recognize different odors. (Biswas, 2014) If we could not smell our test would be blander. Taste, or the perception of flavor, is a result of the stimulation of receptors on the tongue and olfaction. Taste occurs when the chemicals of a food or beverage pass over the receptors of the tongue. At the same time, these chemicals release other chemicals that travel through the retronasal route to the nasal pharynx to the olfactory mucosa. The importance of olfaction in flavor is usually ignored, until someone loses the ability. The unawareness that flavor occurs in the nasal passages as well is an illusion that is created by oral capture. There...
Words: 902 - Pages: 4
...stuck to me was the view, smell, and the sound. All the way from beauty of the ocean, how the colors in the sky blended with the motion of the water. I will always remember the sound of pelicans calling each other as they swooped just in front of the orange sunset to scoop the sea water in their flabby necks. Even the taste of the air mixed with the smell of the sand that just made every sense open wide. I will always remember this moment. It was the only time I have ever felt that I had no worry in the world. The view itself would make you never want to leave. The sky blended perfectly from a fire tangerine orange to a soft baby blue. In between the loudest light of red and the quietest shade of blue, lay the deep purple of a night sky waiting for it’s time to take over the sky. The motion of the water drew you in closer to the shining sun just above the water with the moon shining directly above you like a spotlight. The waves were calm with ripples in every direction possible. The tide pushed the shiny wet sand flat as a plate. The shadows of birds flying towards the sun made me think if they were never going to stop until they actually reached the sun. The smell of the ocean is what made this experience one of a kind. The fresh air that wafted in the air gave me the chills that ran up both my arms. The wet sand mixed with the salt in the water making an aroma that would make you have a flashback of your favorite memory. This was my new favorite memory. The sediments in each...
Words: 454 - Pages: 2
...Mary Karr’s poem “Still Memory” is a childhood dream that Karr vividly walks her readers through. Through each stanza Karr is taking her readers through a new snapshot of her old life. Karr does this in small glimpses due to her fear of one day not remembering. In her poem Karr sways back and forth between the whimsicality of a dream and the vivid remembrance of her childhood. The content of the active poem contradicts its title “Still Memory” by displaying sudden changes of time, the human senses and the breakdown of what Mary’s household looked like before death came over her family all through a nostalgic tone. Through the first 4 stanzas of Mary Karr’s poem “Still Memory” one is given a feeling of what mornings were like at her house through...
Words: 956 - Pages: 4
...protein. But food also contains memories. Certain smells and tastes can take us back to memories that have been held on to by your brain. Food creates bonds with experiences you've had, good or bad. Me personally, whenever I smell really smoky BBQ, I remember February 2nd 2014, Superbowl 48. It was Denver versus Seattle and me and my brother were in the back yard, hours before any of our guests showed, up making preparations for the food we were about make. I was doing the final cleaning of the grill as my brother was getting his array of seasonings ready. The smell of the mesquite wood chips, the seasonings my brother diligently applied to every cut of meat, and not to be forgotten, my mother, preparing the traditional vegetarian Indian dishes to accommodate everyone, all of these smells and sights come to mind when I smell barbecue. It has been engraved in my brain to relate the smell with these fond memories. Food can build everlasting moments. In my family, where the generation before me originated from India and moved to have all their kids here in the states, food helps tie our two or even three generations together. My cousins and I, although we love traditional cooking, we also appreciate the many styles of food we are surrounded by growing up in America. My parents or in other words the generation before mine, grew up with traditional Indian meals for most of their lives. Eventually, when I started getting older and preparing meals myself, I introduced them to more American...
Words: 517 - Pages: 3
...Resource: The "Chef's Tools: Nose and Tongue" section of the "Smell and Taste: Science of the Senses" video, located in this week's Electronic Reserve Readings. Write a 1,250- to 1,500-word paper that addresses the following: * How do smell and taste affect each other? * Which would you change to make a meal taste better? * If you created the most memorable meal of your life, what sensory elements must be present to emphasize the connection between the chemical senses, emotional memories, and the brain? * Describe the connection created between the chemical senses, emotional memories, and the brain. Include at least two to four peer-reviewed sources. Format your paper consistent with APA guidelines. Click the Assignment Files tab to submit your assignment. Hello my name is Joyce Lopez currently I am working towards my bachloprs degree at the University of Phoenix class psy/345 week fives assignment isto address For topics on ‘ Smell and taste’ How do smell and taste affect each other? Which would you change to make a meal taste better? If you created the most memorable meal of your life, what sensory elements must be present to emphasize the connection between the chemical senses, emotional memories, and the brain? Describe the connection created between the chemical senses, emotional memories, and the brain. Since most of what people perceive as "taste" actually results from their sense of smell, a consumer's taste experience can be improved when...
Words: 470 - Pages: 2
...Everyone has their own special place, a place that brings back memories of the good times. I grew up in a small two bedroom house, in a rural country town. Our house was old and small, but, nonetheless it was home. Even though I haven’t been back to the old house in almost a decade, I will always remember its smell and colors. Growing up, we did not have a lot, but what we did have was cherished. In this paper, I will write about the memories I have of the place I call “home”, let me take you on a visit there. Situated at the end of a dirt road which runs off another, larger county road is the place I call “home”. Here, my mother raised three girls without the help or companionship of a husband. The house set back about 200 feet from the road. As we stroll up the dirt drive lined with rows of wild gladiolas on each side, sits the tidy small, unpainted old frame house. On the porch, I can't help but notice a high-backed rocker on one side and a bench worn smooth by age on the other. Both remind me of the many hours spent here enjoying the weather and view. Turning the door knob and entering the foyer is like taking a step back in time. The door, is the same as when I was a kid, the windows are free of curtains, only shades yellowing from age, pulled at night, as if privacy is needed out here in the boondocks. Mom's big over-stuffed floral couch is set beside the well-stocked bookcase. One lonely picture with the words "Home, Sweet Home" hangs on the wall over the fireplace...
Words: 727 - Pages: 3
...Smell My essay for smell was probably the toughest for me to write. I could not think of a good enough topics to expand and write about to my peer editor. I know how much I loved the scent of homemade cookies, thanksgiving dinners, certain perfumes and more but I did not know what to write about. The topic I chose to write about came from one of my roommates while she was reading a magazine and thought of me. It was something that sparked my interest immediately. I love reading about little things that grab my attention and this one I found to be interesting and my partner would enjoy as well. Writer Bethany Heitman from the magazine Cosmopolitan states, ‘…fascinating news: Researchers have discovered that the smell of cucumber-that’s right, cucumbers- makes women aroused’ (p. 193). Who would have thought that this fresh smelling fruit with their hint of a mild sweetness and bitterness would make your female partner so aroused? Automatically I was hooked on why cucumbers and other foods increased pleasure during sexual encounters....
Words: 1240 - Pages: 5
...identified by our senses of sight and smell and not just taste. This is because food can be identified by just sight alone, and same thing goes for smell as well! Our brains actually view taste as a combination of the senses smell and touch at the same time. So really all sensory information is gathered from the actual substance we a consuming. The way we get this information through sent is located in the back of our mouths and called the “retronasal olfaction. The way we gather this similar same information through smell is located in the nose and called the “orthonasal olfaction”. These methods both influence the perception of flavor, so in this smell influences taste and taste influences smell! Taste and smell are classified under a chemical sensing system called “chemosensation”. The whole entire process of smelling and tasting starts when molecules, which are released from all of the many substances around us, stimulate special nerve cells in the nose and the mouth. These cells transmit messages to the brain, where specific smells or tastes are identified. Our body’s ability to sense chemicals is actually another chemosensory mechanism that contributes to our senses of smell and taste. In this system there are thousands of free nerve endings which are mainly located on the moist surfaces of the eyes, nose, mouth, and throat to identify different sensations. Taste and smell are still separate senses with their own receptor organs but smell and taste affect each other in many...
Words: 1370 - Pages: 6
