Mon, 31th Aug 2015, 22:23 Two birds with one stone, as they say!
My EE 306 students: This email to you all is to solve two problems. First, I want to make sure we are all connected via email. I will send you a lot of email throughout the semester, and I want to be sure you get it all. Recall, I said that you need to check the EE306 webpage every other day. Sometimes I don't want you to wait that long and so I send email directly to you. In class on Wednesday I am going to check to see if anyone did not get this email. If you are reading this, you are not one of them. The second thing this email is going to do is respond to a question one of my TAs sent me in email an hour ago. The TA wrote: > Dr Patt, > > I forgot to mention this earlier, but a couple of students asked me if data > types are a part of HLL, or ISA. I think you didn't mention it when you > were talking about it. Maybe you could bring it up on Wednesday? > > Thanks, > <<name withheld to protect the identity of the conscientious TA>> Like too many terms in computer technology, the term "data type" is used in different contexts, and so the correct answer to your question is: both! In EE 306, we are concerned mostly with the ISA, and only incidentally with high level languages. So, in 306, when I speak of data type, I am referring to the ISA. To understand how it pertains to the ISA means first of all, one needs to understand what an ISA is. You will become very familiar with the notion of ISA in a few weeks so I do not want to belabor the definition here. My automobile analogy for some reason did not work this semester, so I am reluctant to spend more time on it now. It is not necessary for you to understand it now, and I am concerned that it will confuse you further unnecessarily now. You will see it in a very few weeks, and then you will understand it (trust me!). However, to satisfy those in the class who have had no trouble getting the concept of ISA, I will make one additional comment. For those of you who are still confused by the notion of ISA, please stop reading now, but save my comment for three weeks from now, and look at it then. It really does not matter if you understand it now, or have to wait until we get to chapter 5 in the book. My additioal comment: The ISA consists of, among other things, all the instructions that the computer can execute, and everything that is needed to carry out the work of each instruction. For example, if one of the instructions the computer can execute is to add two numbers, those two numbers must be represented with bits such that the computer can perform the addition with that representation of those bits. We say that representation is a data type because there are instructions in the computer that will do its job on numbers when they are represented in that way. If this does not help, then please wait until we get to chapter 5. I promise it will make sense then. Yale Patt