8/4/2023 0 Comments Two bits meaning![]() ![]() Here are the binary encodings of the words "YES", "NO", and "MAYBE": The longest word is 5 ASCII characters so the field we would have to use for all three would be 5 bytes (40 bits) long. Imagine what would happen if I wanted to actually communicate the actual words, “Yes”, “No”, or “Maybe”. I still have only 3 possible meanings (Yes, No, and Maybe). Here’s one point to take away from this (so far): I am using MORE bits but my message DOES NOT contain any more information. Now when I want to say ‘Yes’, ‘No’ or ‘Maybe’ to you I will have to communicate 8 bits rather than the original two bits. For simplicity, let’s say that these are our mappings (Note: in real life they are different): Y = 00000000 In a computer each ASCII character is represented using an 8-bit value. Now let’s say that instead of using two binary bits to communicate Yes|No|Maybe we decide to instead use the characters “Y”, “N”, and “B” instead. But we have only defined three meanings in our example). ![]() Using 2 binary bits you can communicate 3 different meanings (Four, really. So, the MINIMUM number of binary bits we would have to use to communicate the different meanings is 2, with one bit combination (11) not used for anything. the ’11’ was information rather than being undefined)). If you were to send you a “11”, it would not mean anything to me (unless we agreed later on that it now meant something (i.e. If you want to say “No”, you communicate “01” and a “Maybe” is communicated by you sending me a “10”. If you want to say “Yes” in response to something I ask you, you can communicate “00” to me. We could agree on the following ‘meaning’-to-binary mappings: So let me try asking it in a seemingly more complicated but different way: “If you wanted to communicate to me one of a range of possible values and you wanted to do it using only binary bits, how many binary bits would you have to use to be able to communicate any of the possible values?”įor example, let us suppose you want to communicate one of three (3) possible values: Well, I know it didn’t make sense to me, at least. Basically, it’s because the binary number system is used in programming in assembly language that bit shifting becomes a commonly used operator.That sentence, in the context of typical use of those words (information & message), doesn’t immediately make sense to most people. Bit shifting is also used a lot in assembly programming because microcontrollers and microprocessors usually rely on flags, which are represented by individual bits. Signed integers are shifted using arithmetic while logical bit shifting is used on unsigned integers. In C and C++, there is only one shift right operator (>) the kind of shift to be done is determined by the type of integer being shifted. Logical left shift and arithmetic left shift have the same effect so Java only has a single left shift operator (>) while the logical is (>). In most cases, shifting is treated as circular so when shifting to the left, the leftmost value becomes the rightmost value, and vice versa. For example, if the value “0001” or “1” is shifted left, it becomes “0010” or “2,” shifted to the left again it becomes “0100,” or “4.” Shifting to the right has an opposite effect of dividing the value by two per shift. Logical bit shifting may be useful for multiplying or dividing unsigned integers by powers of two. There are also two kinds of bit shifting, logical and arithmetic. For example, shifting the operand one value to the left or shifting the bits “n” values to the right. There are two variations to bit shifting, shift right and shift left, and it is further defined by the number of places in which the shift should occur. Bit shifting is often used in programming and has at least one variation in each programming language.īit shifting may also be known as a bitwise operation. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |