电子信息工程专业英语考试要点总结(3)

CDMA 认为多路信号之间是线性相加的。

3.Motherboard -This is the main circuit board that all of the other internal

components connect to . The CPU and memory are usually on the

motherboard . Other systems may be found directly on the motherboard

or connected to it through a secondary connection . For example , a sound

card can be built into the motherboard or connected through PCI .

主板：所有其他内部组件都和主板连接。通常，CPU 和内部都

位于主板上。其他组件可能直接位于主板上，也可能通过某种方式连

接到主板上。例如，声卡可以置于主板上，也可以通过PCI 总线连接

到主板上。

4.In practical terms , this means that one or two layers of metal

interconnect must be designed. Since an integrated circuit requires seven

or more processing stages , all the processing steps other than the final

metalization can be completed in advance . Because the uncommitted

gate arrays can be produced in volume ,the cost of each device is

relatively small.

从实现角度看，就是要设计一层或两层的金属互连线。集成电路

的制造流程分为七个步骤（或更多），除去最后一步“金属化”

(metallization)之外，其他步骤都可以提前完成。由于门阵列可以大量

生产，所以单个器件成本就比较低。

5.Physical layer communications : FPGAs have long used to implement

the glue logic that interfaces between physical layer communication

chips and high-level networking protocol layers . The fact that today's

high-end FPGAs can contain multiple high-speed transceivers means that

communications and networking functions can be consolidated into a

single device.

物理层通信：长久以来，FPGA 用于实现通信芯片和高级网络协

议之间的“胶连”逻辑。实际上，今天的高端FPGA 可以容纳多个高

速无线收发器——即可将通信和网络功能固化于单个器件中。

6.One of the most important applications of VHDL is to capture the

performance specification for a circuit , in the form of what is commonly

referred to as a test bench . Test benches are VHDL descriptions of circuit

stimuli and corresponding expected outputs that verify the behavior of a

circuit over time . Test benches should be an integral part of any VHDL

project and should be created in tandem with other descriptions of the

circuit.

VHDL 最重要的应用之一是以所谓“测试平台”（test bench）的

形式记录电路的性能指标。“测试平台”是验证电路时域行为的激励

源及相应期望输出的VHDL 描述。在VHDL 工程项目中，“测试平台”

是必不可少的，应该和其他电路描述一同创建。

7.A digital signal is a numerical representation of the analog signal .It

may be easier and cost effective to process these signals in the digital

world .In the real world ,we can convert these signals into digital signals

through the analog-to-digital converter ,process the signals,and if