810-073479-215 處理器和存儲器

網(wǎng)卡上面裝有處理器和存儲器(包括RAM和ROM)。網(wǎng)卡和局域網(wǎng)之間的通信是通過電纜或雙絞線以串行傳輸方式進(jìn)行的,而網(wǎng)卡和計(jì)算機(jī)之間的通信則是通過計(jì)算機(jī)主板上的I/O總線以并行傳輸方式進(jìn)行。因此,網(wǎng)卡的一個(gè)重要功能就是要進(jìn)行串行/并行轉(zhuǎn)換。由于網(wǎng)絡(luò)上的數(shù)據(jù)率和計(jì)算機(jī)總線上的數(shù)據(jù)率并不相同,因此在網(wǎng)卡中裝有對數(shù)據(jù)進(jìn)行緩存的存儲芯片。

分類:

描述

810-073479-215 處理器和存儲器

網(wǎng)卡上面裝有處理器和存儲器(包括RAM和ROM)。網(wǎng)卡和局域網(wǎng)之間的通信是通過電纜或雙絞線以串行傳輸方式進(jìn)行的,而網(wǎng)卡和計(jì)算機(jī)之間的通信則是通過計(jì)算機(jī)主板上的I/O總線以并行傳輸方式進(jìn)行。因此,網(wǎng)卡的一個(gè)重要功能就是要進(jìn)行串行/并行轉(zhuǎn)換。由于網(wǎng)絡(luò)上的數(shù)據(jù)率和計(jì)算機(jī)總線上的數(shù)據(jù)率并不相同,因此在網(wǎng)卡中裝有對數(shù)據(jù)進(jìn)行緩存的存儲芯片。
在安裝網(wǎng)卡時(shí)將管理網(wǎng)卡的設(shè)備驅(qū)動程序安裝在計(jì)算機(jī)的操作系統(tǒng)中,這個(gè)驅(qū)動程序以后就會告訴網(wǎng)卡,應(yīng)當(dāng)從存儲器的什么位置上將局域網(wǎng)傳送過來的數(shù)據(jù)塊存儲下來。網(wǎng)卡還要能夠?qū)崿F(xiàn)以太網(wǎng)協(xié)議。
網(wǎng)卡并不是立的自治單元,因?yàn)榫W(wǎng)卡本身不帶電源而是使用所插入的計(jì)算機(jī)的電源,并受該計(jì)算機(jī)的控制,因此網(wǎng)卡可看成為一個(gè)半自治的單元。當(dāng)網(wǎng)卡收到一個(gè)有差錯的幀時(shí),它就將這個(gè)幀丟棄而不必通知它所插入的計(jì)算機(jī)。當(dāng)網(wǎng)卡收到一個(gè)正確的幀時(shí),它就使用中斷來通知該計(jì)算機(jī)并交付給協(xié)議棧中的網(wǎng)絡(luò)層。當(dāng)計(jì)算機(jī)要發(fā)送一個(gè)IP數(shù)據(jù)報(bào)時(shí),它就由協(xié)議棧向下交給網(wǎng)卡組裝成幀后發(fā)送到局域網(wǎng)。
隨著集成度的不斷提高,網(wǎng)卡上的芯片的個(gè)數(shù)不斷的減少,雖然現(xiàn)在各廠家生產(chǎn)的網(wǎng)卡種類繁多,但其功能大同小異。網(wǎng)卡的主要功能有以下三個(gè):
1. 數(shù)據(jù)的封裝與解封:發(fā)送時(shí)將上一層交下來的數(shù)據(jù)加上首部和尾部,成為以太網(wǎng)的幀。接收時(shí)將以太網(wǎng)的幀剝?nèi)ナ撞亢臀膊?,然后送交上一層?br /> 2. 鏈路管理:主要是CSMA/CD協(xié)議的實(shí)現(xiàn);
3. 編碼與譯碼:即曼徹斯特編碼與譯碼。

810-073479-215 處理器和存儲器

A network card contains a processor and memory (including RAM and ROM). The communication between the network card and the LAN is carried out by serial transmission through the cable or twisted pair, while the communication between the network card and the computer is carried out by parallel transmission through the I/O bus on the computer motherboard. Therefore, an important function of network cards is to perform serial/parallel conversion. Since the data rate on the network and the data rate on the computer bus are not the same, a memory chip is installed in the network card to cache the data.
When installing the network card, install the device driver that manages the network card in the computer’s operating system. This driver will later tell the network card where to store the data block transferred from the LAN from the memory. The network card must also be able to implement the Ethernet protocol.
The network card is not an autonomous unit, because the network card itself does not have a power supply but uses the power supply of the inserted computer and is controlled by the computer, so the network card can be seen as a semi-autonomous unit. When the network card receives an errant frame, it discards the frame without notifying the computer it is plugged into. When the network card receives a correct frame, it uses an interrupt to notify the computer and deliver it to the network layer in the protocol stack. When the computer wants to send an IP datagram, it is sent from the protocol stack down to the network card to assemble into frames and then sent to the LAN.
With the continuous improvement of integration, the number of chips on the network card continues to decrease, although there is a wide variety of network cards produced by various manufacturers, but its function is much the same. The main functions of network cards are as follows:
1. Data encapsulation and decapsulation: When sending, the data handed down by the previous layer is added to the header and tail to become the Ethernet frame. When receiving Ethernet frames, the header and tail are stripped, and then sent to the upper layer;
2. Link management: mainly the implementation of CSMA/CD protocol;
3. Coding and decoding: namely Manchester coding and decoding.
公司介紹:
成都陽光不斷創(chuàng)新致力于提升停產(chǎn)的自動化零件供應(yīng)水平,無論客戶身處何地,無論所需配件多么稀有,我們總能將客戶與所需產(chǎn)品緊密連接 ,成都陽光零部件覆蓋廣泛。
急切需要自動化或控制零件? 全新、Used和已停產(chǎn)的自動化機(jī)械零件的全球供應(yīng)商。
客戶支持快速響應(yīng)
合作伙伴網(wǎng)絡(luò)橫跨各個(gè)大洲
全球合作伙伴網(wǎng)絡(luò)




Company Introduction:
Chengdu Sunshine Xihe Co., Ltd. specializes in one-stop procurement consulting for imported industrial spare parts, offering original equipment and professional discontinued parts services. We are committed to providing efficient and reliable automation solutions for our customers. Customer support fast responseThe network of partners spans all continentsGlobal partner networkAlways achieve more delivery, be it parts, service or speed



始終實(shí)現(xiàn)更多的交付,無論是零件、服務(wù)還是速度