【正文】
調用相應處理程序 (或稱服務程序 )進行服務的過程。當執(zhí)行轉移指令時,依據(jù)轉移條件的產生結果,可能為順序取下條指令;也可能轉移到新的目標地址取指令,從而使流水線發(fā)生斷流。 只有取數(shù) /存數(shù)指令訪問存儲器,其余指令的操作都在寄存器之間進行; ( 2) CPU 配備大量的通用寄存器,以寄存器-寄存器方式工作,減少訪存操作; ( 3) 強調指令流水線的優(yōu)化,使大多指令可在一個時鐘周期內執(zhí)行完畢; ( 4) 采用由陣列邏輯實現(xiàn)的組合電路控制器,不用或少用微程序; ( 5) 采用優(yōu)化編譯技術,對寄存器分配進行優(yōu)化,保證流水線暢通。 ? 組相聯(lián)映射 這種方式是前兩種方式的折衷方案。 朝+∞舍入 對正數(shù)來說 ,只要多余位不全為 0 則向最低有效位進 1;對負數(shù)來說則是簡單的截尾。如果判知兩個操作數(shù)x或y中有一個數(shù)為 0,即可得知運算結果而沒有必要再進行后續(xù)的一系列操作以節(jié)省運算時間。在對階時總是使小階向大階看齊,即小階的尾數(shù)向右移位 (相當于小數(shù)點左移 ) ,每右移一位其階碼加 1,直到階碼相等 (3) 尾數(shù)求和運算 對 階結束后,即可進行尾數(shù)的求和運算。 SRAM(靜態(tài) RAM: Static RAM) ,但集成度低,功耗和價格較高 DRAM(動態(tài) RAM: Dynamic RAM) MOS管為基本存儲單元 ( Refresh)操作 、價格低、功耗小,但速度較 SRAM慢 DRAM的刷新方式: 集中式 :在刷新間隔內,前段時間進行正常操作,不刷新;需要刷新時,暫停讀 /寫周期,集中刷新整個存儲器, 由于刷新集中進行,會造成芯片 “ 死時間 ” 過長;因為芯片在刷新過程中,禁止了正常的讀 /寫操作 分散式 : 把一個存儲周期分為兩半,前半段時間用來讀/寫操作或維持信息,后半段時間作為刷新操作時間,加長了系統(tǒng)周期,刷新過于頻繁 多模塊交叉存儲器 : 方式 1:順序方式 某個模塊進行存取時,其他模塊不工作,某一模塊出現(xiàn)故障時,其他模塊可以照常工作,通過增添模塊來擴充存儲器容量比較方便。虛擬 存儲器指的是主存~外存層次。 時鐘周期 : 通常稱為節(jié)拍脈沖或 T 周期。 (3) 中斷和同步總線 :用于處理帶優(yōu)先級的中斷操作,包括中斷請求線和中斷認可線。然后執(zhí)行中斷處理程序 , 由軟件完成中斷服務。s ancient indigenous religion, while Du jiang yan is considered to be the oldest functioning watercontrol project in the world. Chengdu ranked third in tourist facilities, management and services among 60 Chinese cities in a customer satisfaction survey released last year. But, Li added that efforts are still needed to develop more tourism products, improve English services and provide accurate translation of traffic signs and scenic billboards. Zhao Yun, chairwoman of British Chamber of Commerce Southwest China, told China Daily that his colleagues found the policy very convenient. A British client once flew here and stayed for just one day to check her ordered goods, she said. Zhao was born in Shanxi province, but she has lived in Chengdu for more than 10 years. My life was like a running race moving from place to place. I also lived in Beijing and Shanghai before, she said. But Chengdu is a place that you never want to leave once settling down. It is now my second hometown, she said. If the environment is further improved, the city will attract more people to visit and live, with the 72hour visafree policy and pelling conditions in transportation, culture, climate and cuisine, he said. Foreigners also gave positive feedback on the policy. A spokesman from Dell Inc said the pany has a global hub of operation