【正文】
法 近期最少使用 (LRU)算法 隨機(jī)替換 虛擬存儲(chǔ)器的基本概念 虛擬存儲(chǔ)器只是一個(gè)容量非常大的存儲(chǔ)器的邏輯模型,不是任何實(shí)際的物理存儲(chǔ)器。此時(shí)程序的邏輯地址稱為虛擬地址 (虛地址 )。 可按程序員要求,在主存中建立多個(gè)堆棧; RISC技術(shù)的主要特征: ( 1) 一個(gè)有限的簡(jiǎn)單指令集: 指令周期 : CPU 從內(nèi)存取出一條指 令并執(zhí)行這條指令的時(shí)間總和。第一種稱為 硬布線控制器 , 它是采用時(shí)序邏輯技術(shù)來 實(shí)現(xiàn)的;第二種稱為 微程序控制器 , 它是采用存儲(chǔ)邏輯來實(shí)現(xiàn)的;第三種是前兩種方式的組合。 流水過程中通常會(huì)出現(xiàn)以下三種相關(guān)沖突 , 使流水線斷流。 在流水計(jì)算機(jī)中,指令的處理是重疊進(jìn)行的,前一條指令還沒有結(jié)束,第二、三條指令就陸續(xù)地開始工作。 為了減小轉(zhuǎn)移指令對(duì)流水線性能的影響,常用以下兩種轉(zhuǎn)移處理技術(shù): (1) 延遲轉(zhuǎn)移法 (2) 轉(zhuǎn)移預(yù)測(cè)法 微程序控制器工作原理框圖 如下: 根據(jù)連接方式不同,單機(jī)系統(tǒng)中采用的總線結(jié)構(gòu)有三種基本類型: 單總線結(jié)構(gòu) 雙 總線結(jié)構(gòu) 三總線結(jié)構(gòu) 當(dāng)代總線分成如下四部分 : (1) 數(shù)據(jù)傳送總線 :由地址線、數(shù)據(jù)線、控制線組成。 1. 串行傳送 當(dāng)信息以串行方式傳送時(shí),只有一條傳輸線,且采用脈沖傳送。信息有多少二進(jìn)制位組成,就需要多少條傳輸線,從而使得二進(jìn)制數(shù) “0” 或 “1” 在不同的線上同時(shí)進(jìn)行傳送。 接口部件在它動(dòng)態(tài)連接的兩個(gè)部件之間起著 “ 轉(zhuǎn)換器 ” 的作用,以便實(shí)現(xiàn)彼此之間的信息傳送。 中斷源一旦需要 CPU 為其服務(wù)時(shí),就向 CPU 發(fā)出請(qǐng)求,CPU一般在當(dāng)前指令執(zhí)行完,且狀態(tài)為允許中斷的情況下響應(yīng)該請(qǐng)求。 中斷處理過程的四個(gè)問題: 問題說明: (1) 盡管外界中斷請(qǐng)求是隨機(jī)的,但 CPU 只有在當(dāng)前一條指令執(zhí)行完畢后,即轉(zhuǎn)入公操作時(shí)才受理設(shè)備的中斷請(qǐng)求,這樣才不致于使當(dāng)前指令的執(zhí)行受到干擾。這些操作叫做保存現(xiàn)場(chǎng)。中斷周期由硬件實(shí)現(xiàn),而中斷服務(wù)程序由機(jī)器指令序列實(shí)現(xiàn)。s level of internationalization. The policy will also bring direct economic revenue, Li said. Chengdu has many cultural legacies and is also a paradise for panda lovers with the world39。s public security bureau shows some 100 foreign visitors enjoyed the 72hour policy by the end of March, most of them from the United States, the United Kingdom and Germany. Chengdu also reported robust growth in its overall tourist industry last year. Official statistics show that it received some 150 million tourists last year, an increase of 28 percent from 2021. Around million came from abroad, an increase of 12 percent. Total revenue from tourism surpassed 133 billion yuan ($). During his visit to Kazakhstan in September, Chinese President Xi Jinping proposed that China and Central Asia join hands to build a Silk Road economic belt to boost cooperation. The idea has been w idely echoed in Central Asian countries, being an encouraging blueprint for Chinese areas along the Silk Road that has linked Asia and Europe for more than 2,000 years. In the next three weeks, China Daily reporters will travel through the belt in China and in Kazakhstan, Uzbekistan and Turkey. They w ill show the progress and expectations of the countries, businesses and peoples on the route. Shaanxi the start of the ancient Silk Road has positioned itself as the new starting point for the development of the Silk Road Economic Belt, w hich w ill strengthen China3