Senior Programmer Exam Question Analysis - Computer Hardware Basic Knowledge (Advanced Programmer - level) Advanced Programmer Qualification and Level Examination Test Test Test Test Test 4 Question: 1. Types of random memory. 2. Virtual memory characteristics and working principle. 3. Data reliability encoding CRC and working principle. 4. Redimonize the characteristics of the computer RISC. I. Type and Features of the main memory (ninth question) Main memory is used to store the and common instructions and data required for running procedures. It is the part directly accessed by the CPU. The main requirement of the host's main memory is fast. Main memory typically includes, random read memory RAM and read-only memory ROM. 1. It is possible to read and write, as long as it is constantly moving its storage, the constant memory chip is called static random read memory SRAM, and the unit storage principle is similar to the trigger. 2. It can be used to read and write, but it is necessary to continuously refresh to keep the chip in which information is stored is called dynamic random readout memory DRAM, which is composed of dynamic MOS circuitry. With capacitance charging to store data but because the circuit itself has a leakage, it is necessary to constantly constantly supplement charging to maintain its storage. Note that DRAM must refresh even when it is constantly electricity, but this refresh is automatically carried out without the need to intervene. 3. The manufacturer is called only read memory reservoir ROM before the product is factory factory. Users cannot change content, often used to store fixed programs. 4. The user feels inconvenient when using the ROM, sometimes it is time to change the content of the ROM, and EPROM can be used as an erased programmable read-only memory. However, each erase requires the ultraviolet light to illuminate this chip for 15 to 20 minutes, and special devices must be used when writing data. Therefore, it is still not written during the machine operation. 5. A new type of memory flash memory FM has been available. It is characterized by a signal that can quickly erase a part or all of the chip content in a few seconds, but cannot erase the specified unit (byte) separately. Second, the virtual memory (Chain 10) 1. The main memory is fast, but the capacity is small, and the CPU can access directly. The size of the exemption is slow, and the CPU cannot be accessed directly. The user's program and data are usually placed in the absence. Therefore, you need to be sent to the owner and the exemplary. It is very inconvenient to intervene from the user to intervene. The virtual memory is used to solve this contradiction, and the user feels that he can directly access the entire inside and externally stored space without user intervention. Therefore, a large amount of speed is relatively fast, becomes a main component of the virtual memory. 2. The data in the hard disk in the virtual memory is similar to the scheduling method of the data in the main memory similar to the scheduling method of the cache Cache. That is, the data that is often accessed is transferred into the high-speed main memory. Unwanted data is sent back to the hard disk with a certain alternative algorithm. These transferred operations are automatically completed by the virtual memory. 3. The user program uses virtual access to the entire virtual space, while the instructions can only access the main memory space. Therefore, the virtual real address transformation must be performed, and the unit content that does not transfer the unit content of the main memory will be accessed again. 4. The virtual address conversion is the key in the virtual memory. In order to improve the conversion speed, the conversion is usually used to support this conversion, that is, put the negative page in the associated memory, the associated memory is accessed, and directly find you want to access the virtual page number Whether to get the relevant real page number in the associated memory. Third, data reliability encoding CRC (Eleventh question) 1. The data is in the computer that the reliability directly affects computer reliability, and it will be very important to detect and correct the generated data errors through encoding techniques. 2. Using the die two divider when generating a CRC check code is done in the model two operation. Modules do not produce and borrow.
