Home > Courses > 2P32 > 2018-2019 Problem-based tutorial #1 What does this circuit do? start by examining M=High, Cn=Low; ignore X and Y. what is pin (14) ? what is pin (16) ? Why is it called Cn+4? What is Cn? Student feedback  -------------------------------------------------------------------- From: lw18pq on 2/14/19 5:09 PM It would have definitely been a better start to look at the block diagram, but I wouldn't have known how to start. That's where I'd ask for help next time. Having that would have saved me a lot of time simulating the first part of the circuit. As a team, we could have communicated more. I noticed that from making a small discovery it was incredibly difficult to gain traction on the next part of the problem. I could see what something did but I had a hard time translating that to a why or how. Like at the beginning with setting M to high and C to low. I was scared to be wrong and I didn't want to say much especially since no one else was talking. In terms of specific problems, I had no idea it was a carry, I still don't know what m is. From looking at the questions posed, I know how approximately how pin 14 works but I don't get the significance. To do better next time, it could be a good idea to list these questions and discuss as a group which ones are important and which ones less to the operation of the circuit as a whole. The block diagram would be good to develop together. As far as the math idea goes, sitting together and talking about it would be good. I honestly think it's not enough time to get to know the teammates and develop good communication strategies. Better next time! -------------------------------------------------------------------- From: re17wj on 2/17/19 1:27 PM On Feb 14, we conducted our first PBT, and out of that, it was shown just how ineffective our initial work practices were. For any team, there are a few things that are paramount: •Communication •A Plan •Time In terms of the last PBT, we had none of these. Time is the most important factor, and for a below average group size mixed with no time to familiarize ourselves with each other (especially the big factor that nobody would take charge), we did pretty well. The PBT was a math thing, and as I worked, it always bugged me what these outputs of A, B and S would actually do mixed together. The contributions from the other members showed great lights into the scheme of the circuit, but I did not provide much insight. What we need for future PBT’s, is for someone to take charge and distribute roles based on our strengths, and a determinate goal to drive us to communicate our ideas to each other. After further inspection after the allotted time that day revealed the exact characteristics of the circuit, as well as the chip it's based on. Searching upon the term ”4-bit ALU” (ALU meaning Arithmetic logic unit), revealed an interesting Wikipedia page containing the exact same picture seen in the PBT, and thus bringing me to the page for a 74181 chip, used as a logic core for many historic minicomputers. Before this however, it was discovered after many attempts at total boolean logical construction that different operations are conducted based on what M and Cn are set to. M determines if the circuit will be used as a logic operation (AB, A+B, etc.), or an arithmetic operation (values of A+B, etc.), as well as including basic logical 0 and logical 0. The specifics of which operation is conducted is determined by S0−S3. -------------------------------------------------------------------- From: ls09wo Not submitted. --------------------------------------------------------------------