電大?？朴嬎銠C組成原理考試小抄【御用版(參考版)
2025-06-09 14:57本頁面
【正文】 an, the starting point of the ancient Silk Road, a trade channel established more than 2,000 years ago linking China, Central Asia and Europe. 。s cooperation w ith Central Asian countries, a senior official said. Shaanxi Governor Lou Qinjian said the province is fresh, rich and unique, as it was when it anchored one end of the ancient Silk Road. It is the best option for acmodating industrial transfers from East China or the w orld at large, he said on Wednesday in Xi39。s business development. Rudy Buttignol, president of the public broadcasting pany in British Columbia, Canada, said his work requires frequent travel to Chengdu and the policy makes the trips easier. Data from the city39。s largest breeding and research center. Three days are long enough for foreign visitors to visit those iconic tourist spots, he noted. The city is home to the remains of the Jin sha civilization that dates back more than 3,000 years as well as the Qing cheng Mountains and the Du jiang yan irrigation system. Qing cheng has long been recognized as the birthplace of Taoism, China39。s 72hour visafree policy has attracted wide attention from both Chinese and foreign experts and businessmen since it took effect on Sept 1 last year. The program permits citizens from 51 countries and regions including the United States, Australia, Canada and Japan who have valid visas and flight tickets to a third country to spend three days in the city. The capital of Sichuan province is the first city in the western region of China to offer foreign tourists a threeday visa and the fourth nationwide to adopt the policy following Shanghai, Beijing and Guangzhou. Li Zhiyong, deputy dean of the tourism institute at Sichuan University, said the move contributes to a large increase in the number of overseas tourists and raises the city39。后者除執(zhí)行保存現(xiàn)場、恢復(fù)現(xiàn)場、開放中斷并返回主程序任務(wù)外，還對要求中斷的設(shè)備進行服務(wù)，使其同CPU 交換一個字的數(shù)據(jù)，或作其他服務(wù)。 (4) 中斷處理過程是由硬件和軟件結(jié)合來完成的。 (3) 當(dāng) CPU 響應(yīng)中斷后，正要去執(zhí)行中斷服務(wù)程序時，可能有另一個新的中斷源向它發(fā)出中斷請求。 (2) 為了在中斷服務(wù)程序執(zhí)行完畢以后正確地返回到原來主程序被中斷的斷點 (PC 內(nèi)容 )而繼續(xù)執(zhí)行主程序，必須把程序計數(shù)器 PC 的內(nèi)容，以及當(dāng)前指令執(zhí)行結(jié)束后 CPU 的狀態(tài) (包括寄存器的內(nèi)容和一些狀態(tài)標(biāo)志位 )都保存到堆棧中去。外界中斷請求信號通常存放在接口中的中斷源鎖存器里，并通過中斷請求線連至 CPU，每當(dāng)一條指令執(zhí)行到末尾，CPU 便檢查中斷請求信號。中斷處理程序結(jié)束，執(zhí)行返回指令返回斷點，繼續(xù)執(zhí)行原程序。并由硬 件自動關(guān)中斷（防止在保留斷點和程序轉(zhuǎn)移過程中又有新的中斷請求發(fā)生）、保留斷點、轉(zhuǎn)到相應(yīng)的中斷處理程序入口處。 輸出過程： (1) CPU 把一個地址值放在地址總線上，選擇輸出設(shè)備； (2) CPU 把數(shù)據(jù)放在數(shù)據(jù)總線上； (3) 輸出設(shè)備認為數(shù)據(jù)有效，從而把數(shù)據(jù)取走 中斷 是一種在發(fā)生了一個異常事件時，調(diào)用相應(yīng)處理程序 (或
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