These data are part sorted out on the basis of various chiefs read the article above, by reference.
1. What computer system consists of two parts? What computer system performance depends on?
The computer system is composed of hardware and software, a computer system to measure the pros and cons is based on several indicators to determine the comprehensive, functional section contains the hardware, but also includes software section.
2. Computer system 5 level in the hierarchy of which five layers from bottom to top? What is the physical machine, which is a virtual machine?
1) micro-program machine, traditional machine, OS machine, machine assembly language, high-level language machine
2) micro-program machines and conventional machine is physical machines, other virtual machine.
3. In a computer system configuration, what is the translation? What is the explanation?
Is to translate the words of a programming language all at once into another language, the word is a sentence to explain the interpretation and implementation, and in general about what is the difference between fall.
4. The main features of von Neumann machines?
There are five characteristics:
1 by the arithmetic unit, a memory, a controller, input and output these five components
2. The instructions and data in binary form in the memory
3. In the system operator center
4. The instruction has an opcode and address code
5. instruction sequence exists, a certain order to the output
The main memory, what is MAR, what is the MDR, the largest memory capacity determined by what?
Address is the address register MAR, the data register MDR is DATA, the maximum capacity of the memory by the number of bits of the address register and data register determined
6. What is the machine word, what word is stored, what is the instruction word length?
Is a machine word operations executed by a CPU of the number of bits, number of bits stored in a memory word length is the longest storage unit, the instruction word length is the longest of the binary digits machine instructions
7. The system according to different bus transfer information is divided into several categories? Is one-way or two-way?
It is divided into a data bus, an address bus and a control bus
in which the data bus and control bus is bidirectional, unidirectional bus and the address issued by the CPU.
8. According to the way the memory, which can be divided into four? What are random access memory, which belongs to the serial access memory?
1) can be divided into a random access memory (RAM), a read only memory (ROM), sequential memory (SAM) and a direct memory (the DAM);
2) belong to a random access memory RAM and read only memory, i.e. independent of the physical address access time ;
3) sequential memory (typically such as tape) and a direct memory (such as disks typically) belongs serial memory, i.e., the access time related to the physical address.
9. Which three indicators to measure memory usage? Register, cache (cache), main memory, which is the fastest? Which is the most expensive?
Namely, capacity, speed and price. Which registers the fastest, most expensive main memory
10. Common storage system hierarchy What are the two? How to transparency? What used to solve their problems?
One is the main memory and secondary storage hierarchy, mainly used to solve the problem of insufficient capacity of main memory, for application designers transparent, opaque system programmer. Another is the main memory and the cache hierarchy, mainly to solve the problem and the main memory does not match the speed of the CPU, all transparent to the programmer.
Word storage 11. There are two big end and the small end mode in the storage unit. What is the meaning of each? x86 uses Which memory?
1) big-endian mode: the low word of the high address in memory, the presence of low and high-order word memory address; and
2) the small end: the presence of low low word address in memory, the presence of the high-order word of memory high address.
3) x86CPU is used in the small end.
12. What is the access time? What is the access cycle? Which is bigger?
Start a memory access time from start to end of the process, two access cycle is the time interval starting memory, wherein the access comprises access time period.
13. The random access memory which contains two categories? What needs to be refreshed? Please briefly compare in terms of speed, capacity, price, etc.
1) Static SRAM: principle implemented using latches;
2) dynamic DRAM: capacitive principle implemented, need to be refreshed.
3) compared to the dynamic RAM, static RAM, fast speed, small-capacity, high price, generally used for cache, the dynamic RAM memory is generally used. (Anyway, the higher the value of static RAM)
14. The three ways to improve memory access speed.
1) high-speed components; (hardware)
2) The storage hierarchy: cache- main memory structure; (software)
3) adjustment of main memory structure: comprising (a monomer multiword software, multibody parallel in two ways )
15. What is interrupt?
Overall, the system is in operation, an exception is encountered. The system began to take measures to interrupt. Stop the current run, and save the corresponding site, and then to deal with the exception, after the recovery site, continue.
16. The basic flow of the interrupt service routine which includes four parts?
1 ,. interrupt service protection site 2. 3. 4. recovery site interrupt return
17.CPU interrupt response time?
After the end of the current instruction
18. opcode has a fixed length and variable-length two kinds, each having strengths?
1) Fixed length: hardware design convenience, instruction decode time is short;
2) variable length: The average length of compressed opcodes;
19. What is DMA?
Output from the input device here, the direct memory access DMA: Direct Memory Access. Establishing an independent bus connection between the main memory and I / O devices.
20. What is the form of address? What is a valid address?
1) in the form of Address: the address field of the instruction code is generally do not represent the real address of the operand address into a form, referred to as A;
2) Effective Address: the real address of the operand, denoted EA, in the form of addresses by the addressing characteristics and decided together;
21. The data stored in the memory, why should be aligned in accordance with the border?
In order to reduce the number of memory accesses
Instead of using the register 22. When the address code field of the instruction word, which advantages?
1. Reduce the number of memory access
2. improved addressing range
