问题 单项选择题

下列关于中断的叙述中,错误的是

A.时间片到时属于时钟中断

B.目态下执行特权指令将产生程序性中断

C.缺页中断属于自愿性中断

D.打印机完成打印将产生输入输出中断

答案

参考答案:C

解析: 中断机制是现在计算机设施中的基本设施之一。它在系统中起着通信联络的作用,以协调系统对各种外部资源的响应和处理。一般将中断源分为两类:即强迫性中断和自愿性中断。自愿性中断是正在运行程序时有意识安排的,通常由程序员在编制程序时,因要求操作系统提供服务而有意识使用访管指令或系统调用,从而导致中断的。而强迫性中断是正在运行的程序所不期望的,它们是否发生,何时发生都无法预料。这类中断大致有以下几种: 1)输入/输出中断是来自通道或各种外部设备的中断,用以反馈通道或设备的工作状况; 2)硬件故障中断是机器发生错误时的中断,用以反馈硬件在执行过程中出现的故障; 3)时钟中断是硬件或软件时钟到时引起的中断; 4)程序性中断是因运行过程中的问题所引起的中断,用于反馈程序执行过程中出现的意外情况,如目态下执行特权指令、地址越界、虚拟存储中的缺页等。 由上面的介绍可知缺页中断属于强迫性中断中的程序性的中断,而不属于自愿性中断。

填空题


A Sports体育运动
Many animals engage in play,but homo sapiens is the only animal (1) have invented sports.Since sports are an invention,a part of culture (2) than an aspect of nature,all definitions of sports are somewhat arbitrary. (3) sports are a human universal found in every known culture or a (4) unique to modern society depends upon one’s definition of sports.Men and (5) have always run,jumped,climbed,lifted,thrown, and wrestled,but they have (6) always performed these physical activities competitively. Although all literate societies seem to (7) contests of one sort or another in which men, and sometimes women, (8) in displays and tests of physical skill and prowess,sports may be (9) defined as physical contests performed for their own sake and not for (10) ulterior end.According to this strict definition,neither Neolithic hunters nor contestants (11) religious ceremonies such as the ancient Olympic Games were engaged in sports. (12) on the stipulation that sports must be performed for their own sake (13) the paradoxical elimination of many activities which are usually thought of as (14) ,such as exercises done for the sake of cardiovascular fitness,races run (15) satisfy a physical education requirement,ball games played to earn a paycheck. (16) definition also means abandonment of the traditional usage in which"sport,"derived (17) Middle English disporter,refers to any light hearted recreational activity.In the. (18) of some 18th- century aristocrats,a game of backgammon and the seduction of (19) milkmaid were both considered good sport,but this usage of the term (20) become archaic.

单项选择题