TTL是TimeToLive的缩写，该字段指定IP包被路由器丢弃之前允许通过的最大网段数量。TTL是IPv4报头的一个8bit字段。
These data selectors/multiplexers contain full on-chipdecoding to select the desired data sou
This device contains four independent set-reset type flipflopswith one Q output each.
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1、TTL电路TTL电路以双极型晶体管为开关元件，所以又称双极型集成电路。双极型数字集成电路是利用电子和空穴两种不同极性的载流子进行电传导的器件。它具有速度高（开关速度快）、驱动能力强等优点，但其功耗较大，集成度相对较低。根据应用领域的不同...
This device contains four independent gates each of whichperforms the logic AND function. The
This device contains six independent gates each of whichperforms the logic INVERT function. T
This device contains two independent combinations ofgates, each of which perform the logic AN