今日要點:
- DMA和DataBus定義
- which做關系副詞時介詞前置
DMA（直接內存訪問）
Direct Memory Access.
A technique for transferring data directly between two peripherals (usually memory and an I/O device) with only minimal intervention by the processor(沒有謂語動詞齐疙，并非是一句句子膜楷，這么長的描述只是對technique的解釋。).
DMA transfers are managed by a third peripheral called a DMA controller.
直接內存訪問贞奋。一種直接在兩個外設（通常是內存和I/O設備）之間進行數(shù)據(jù)傳輸?shù)募夹g赌厅，它只要處理器最少的介入。DMA傳輸由叫DMA控制器的第三方外設進行管理轿塔。
transfer...between...在...兩者之間傳輸特愿，between表示兩者之間
with only minimal intervention by : 介詞短語
Data bus（數(shù)據(jù)總線）
A set of electrical lines connected to the processor and all of the peripherals with which it communicates.
When the processor wants to read (write) the contents of a memory location or register within a particular peripheral, it sets the address bus pins appropriately and receives (transmits) the contents on the data bus.
連接處理器與所有外設進行通訊的電子線路集。當一個處理器想去寫（讀）某一特定外設中的存儲器地址或寄存器中的內容時勾缭，處理器設置地址總線并在數(shù)據(jù)總線上接收（傳輸）內容揍障。
今日語法要點:
A set of electrical lines connected to the processor and all of the peripherals with which it communicates.
關于這句句子，我覺得滿模糊的俩由。
connected to 到底是動詞的過去式作謂語還是過去分詞做后置定語修飾A set of electrical lines?
我個人偏向與connected to是過去分詞做后置定語
- connected to the processor and all of the peripherals應該是過去分詞做后置定語修飾A set of electrical lines毒嫡，而不是將connected to 理解為謂語
with which其實是狀語從句，which做關系副詞幻梯。
with which it communicates其實是:
which it communicates with.
communicates with為不及物動詞兜畸，將with前置到which前面，形成with which做關系副詞使用礼旅，而這里的it指代的是A set of electrical lines 膳叨。
講的比較暈，先就這樣子吧痘系。等我查好資料再繼續(xù)系統(tǒng)的聊一下吧菲嘴。
這個是其實涉及幾個方面的語法知識，例如:
- 及物動詞和不及物動詞
- which汰翠，where,when,how...等這些核心的語法詞龄坪，到底是做關系副詞還是關系代詞.
