Chapter 1 Introduction tools that are available to you,such as schematic-entry programs,simulators, and HDL co you'll be able to produce good results.Please pay attention to what you're producing with them! 1.6 Integrated Circuits A collection of one or more gates fabricated on a single silicon chip is called an integrated circuit (IC) integrated circuit (IC).Large ICs with tens of millions of transistors may be halt an inch or more on a side,while small ICs may be less than one-tenth of an inch on a side. Regardless ICis initially part ofamuch up to ten inches in diameter,containing dozens to hundreds of replicas of the same IC.All of the IC chips on the wafer are fabricated at the same time,like pizzas that are eventually sold by the in this case.each piece (IC the wafer and defective ones are marked.Then the wafer is sliced up to produce the individual dice,and the marked ones are discarded.(Compare with the pizza- maker who sells all the pieces,even the ones without enough pepp roni!)Each unmarked die is mounted in a package,its pads are connected to the package pins,and the packaged IC is subjected to a final test and is shipped to a customer. Some people use the term“IC”to refer to a silicon die.Someuse“chip”to refer to the same thing.Still others use“IC”or“chip”to refer to the combination ofa silicon die and its package.Digital designers tend to use the two terms inter- changeably,and they really don't care what they're talking about.They don't require a precise definition,since they're only looking at the functional and elec trical behavior of these things.In the balance of this text,we'll use the term /Cto refer to a packaged die. A DICEY A reader of the second edition wrote to me to collect a $5 reward for pointing out my DECISION “glaring”misuse of“dice”as the plural of“die.”According to the dictionary.she said,the plural form of“die”is“dice”only when describing those little cubes with Being stubbom.l asked m friends at the iroprrabu dots d she produced the references to prove i issue.According to the editor. There is,indeed,much dispute over this term.We actually stopped using the term "dice"in Microprocessor Report more than four years ago.I actually prefer the plural"die,".but perhaps it is best to avoid using the plural whenever possible. So there you have it,even the experts don't agree with the dictionary!Rather than cop out,I boldly chose to use"dice"anyway,by rolling the dice. Copyright1999 by John F.Wakerly Copying Prohibited 12 Chapter 1 Introduction DO NOT COPY DO NOT COPY DO NOT COPY DO NOT COPY DO NOT COPY DO NOT COPY DO NOT COPY DO NOT COPY DO NOT COPY Copyright © 1999 by John F. Wakerly Copying Prohibited tools that are available to you, such as schematic-entry programs, simulators, and HDL compilers. But remember that learning to use tools is no guarantee that you’ll be able to produce good results. Please pay attention to what you’re producing with them! 1.6 Integrated Circuits A collection of one or more gates fabricated on a single silicon chip is called an integrated circuit (IC). Large ICs with tens of millions of transistors may be half an inch or more on a side, while small ICs may be less than one-tenth of an inch on a side. Regardless of its size, an IC is initially part of a much larger, circular wafer, up to ten inches in diameter, containing dozens to hundreds of replicas of the same IC. All of the IC chips on the wafer are fabricated at the same time, like pizzas that are eventually sold by the slice, except in this case, each piece (IC chip) is called a die. After the wafer is fabricated, the dice are tested in place on the wafer and defective ones are marked. Then the wafer is sliced up to produce the individual dice, and the marked ones are discarded. (Compare with the pizza￾maker who sells all the pieces, even the ones without enough pepperoni!) Each unmarked die is mounted in a package, its pads are connected to the package pins, and the packaged IC is subjected to a final test and is shipped to a customer. Some people use the term “IC” to refer to a silicon die. Some use “chip” to refer to the same thing. Still others use “IC” or “chip” to refer to the combination of a silicon die and its package. Digital designers tend to use the two terms inter￾changeably, and they really don’t care what they’re talking about. They don’t require a precise definition, since they’re only looking at the functional and elec￾trical behavior of these things. In the balance of this text, we’ll use the term IC to refer to a packaged die. integrated circuit (IC) wafer die A DICEY DECISION A reader of the second edition wrote to me to collect a $5 reward for pointing out my “glaring” misuse of “dice” as the plural of “die.” According to the dictionary, she said, the plural form of “die” is “dice” only when describing those little cubes with dots on each side; otherwise it’s “dies,” and she produced the references to prove it. Being stubborn, I asked my friends at the Microprocessor Report about this issue. According to the editor, There is, indeed, much dispute over this term. We actually stopped using the term “dice” in Microprocessor Report more than four years ago. I actually prefer the plural “die,” . but perhaps it is best to avoid using the plural whenever possible. So there you have it, even the experts don’t agree with the dictionary! Rather than cop out, I boldly chose to use “dice” anyway, by rolling the dice. IC