看的实在头疼,请英语好的哥们帮翻译下: 电气工程及其自动化的专业方向
万分感谢 实在没分了。。。。
A cycle is the smallest unit of time in a microprocessor's universe. Every action that a processor performs is measured by these cycles. It is important, however, to understand that the clock speed is not equal to the number of instructions that a processor can execute in one second. In many computers, some instructions occur within one cycle, but other instructions might require multiple cycles. Some processors can even execute several instructions in a single clock cycle.
Word size refers to the number of bits that a microprocessor can manipulate at one time. Word size is based on the size of the registers in the ALU, and the capacity of circuits that lead to those registers. A microprocessor with an 8-bit word size, for example, has 8-bit registers, processes eight bits at a time, and is referred to as an "8-bit processor." Processors with a larger word size can process more data during each processor cycle, a factor that leads to increased computer performance. Today's personal computers typically contain 32-bit or 64-bit processors.
Cache is sometimes called "RAM cache" or "cache memory." It is special high-speed memory that allows a microprocessor to access data more rapidly than from memory located elsewhere on the motherboard. Some computer ads specify cache type and capacity. A Level 1 cache (L1) is built into the processor chip, whereas a Level 2 cache (L2) is located on a separate chip and takes a little more time to get data to the processor. Cache capacity is usually measured in kilobytes.
As chip designers developed various instruction sets for microprocessors, they tended to add increasingly more complex instructions that each required several clock cycles for execution. A microprocessor with such an instruction set uses CISC (complex instruction set computer) technology. A microprocessor with a limited set of simple instructions uses RISC (reduced instruction set computer) technology. A RISC processor performs most instructions faster than a CISC processor. It might, however, require more of these simple instructions to complete a task than a CISC processor requires for the same task.
Some processors execute instructions "serially"—that is, one instruction at a time. With serial processing, the processor must complete all of the steps in the instruction cycle before it begins to execute the next instruction. However, using a technology called pipelining, a processor can begin executing an instruction before it completes the previous instruction. Many of today's microprocessors also perform parallel processing, in which multiple instructions are executed at the same time. Pipelining and parallel processing enhance processor performance.
字长就是微处理器一次能处理的位数。字长取决于算术逻辑单元里德寄存器的大小和通向寄存器的电路容量。例如,8位字长的微处理器有8位寄存器,一次能处理8位,它称为8位处理器。更长字长的处理器在一个处理周期内能处理更多数据。更长的字长是增强处理器性能的一个因素。当今的个人电脑通常包含的是32位或者64位处理器。
高速缓冲存储器有时叫做数据缓存或者缓存。它是一个高速内存,能让微处理器更快的从主板的其它地方的内存访问数据。一些电脑广告喜欢特别说明缓存的类型和容量。一级缓存被植入到处理器芯片内,而二级缓存位于分离的芯片中,它需要更多时间从微处理器中得到数据。缓存的容量通常用Kb来衡量。
当芯片设计师为处理器开发各种各样的指令集时,他们趋向于增加更多复杂的指令,每个指令需要几个时钟周期。有这种指令集的微处理器使用 CISC 技术。有简单指令集的微处理器使用 RISC 技术。 RISC 处理器处理大部分指令比CISC处理器快。然而,比起CISC处理器,处理同样的任务它可能需要更多的简单指令。
一些处理器是“串行”的处理指令,也就是一次处理一条指令。串行处理中,处理器必须完成一个指令的所有步骤才可处理下一指令。然而,用一种叫做流水线的技术,处理器可以在处理完上一个指令前处理下一个指令。当今的微处理器也能“并行”处理,就是同时能处理多条指令。并行处理增强了处理器的性能。
翻的好累啊,我也是电气的。。。