Hello and welcome to lecture number nine. In this lecture we will explore some of the so called coverage options available for our groups and cover points. So, first, let's see what are the instance specific coverage options. So here's an example I have two variables address and offset. I will cover group called CG one. Now as you notice, I have parameterize it and we saw a similar example in earlier lecture.
With the integer i w and string I comment and we'll see how they get used. This cover group is sample that pauses of clock. Now, first thing I'm doing here is I'm saying option, which is a keyword dot per underscore instance, there's also keyword equal to one. What this means is that track the coverage information for each instance of CD one, there are two instances, CD one instance CD two, it's so attractive Coverage information for each instance of CD one in addition to the accumulative coverage information for the entire hour group CD one. So, you can you can specify this kind of options to make the overall coverage report that you get more meaningful. Similarly, there is option called comment and echoed why comment I comment is the the formal that I use here, this hormone will get the actual comment string from because it's of type string or venue instantiate, so comment for each instance of this color group.
So when there are two instances we can in the in the coverage report, you will see coverage for CG ones and coverage for CG two ns based on a string that I have provided here. This one is a very useful option auto min max. So, as you can see here, I'm not providing any bins here at all. I'm simply saying CounterPoint. ADR, ADR is a variable here. But what I'm also saying is that only create maximum of four automatic bins for this particular counterpoint label AR.
And so, this is another way, when you have an explosion of guard points, bins and so on and so forth. You can provide cover group instance based options to limit certain for example number of beans in this case. This is also another interesting option. It's called dot weight. What this means is that this cover point, this cover point which is labeled offset, it contributes i w times as much to the coverage of an instance of CG one There are two instances for each instance, this particular PowerPoint offset, it can be, it's either two times as much to the coverage of an instance of CG one, then our point AR. So let's say I have, I'm passing in two different weights.
One is for the first incentive two for the second instance is three. So if you if you cover this, all the bins of corporate offset they will have twice or three times as much weight as the beans covered by the PowerPoint, ADR. And this is become important right now there may not look so useful, but when you have a large SOC with hundreds of IPS in it, and hundreds of interfaces and you're trying to make sure everything is covered. As I interface may mean mean more to you. Then PCI Express or the memory interface, and then you want to make sure that that gets covered and it has more weight than the other interfaces. So that's where the weight comes into picture.
This is another example of cover group type options. What we saw was instances specific. And and again, they were called option dot something. Now here we are going to say type underscore option. So type underscore option. Comment means for example, comment for the group CG one as a whole.
Here we saw instance specific comments. Our coverage for this instance can correct for that instance. But here we are, we want to have one particular comment for the entire group as well. And that's where type underscore option comes into picture. Type underscore option, comment, type underscore often got stroke, meaning at anything that you sample in this Covered group, everything that you evaluate in samples needs to take place at the end of the time slot. This is just like dollar stroeve in Verilog.
Or, or even, which I particularly don't recommend, but it's using lb zero and Verilog basically sample and to see if this particular bin have been covered at the end of the simulation time. This way it is exactly what I explained in the previous slide. But here the over over here the wait was for a particular PowerPoint instance specific here it is for the for the whole cover. So that's why I'm saying here that that is specifies the weight of this cover group for computing the overall cumulative coverage of the saved database. And it has to be a constant you cannot have. So the type underscore option dot weight has to be a constant.
But option got weight can be a variable and then you can pass different rates. In specific ways, but for a given cover group, it has to be a constant. And this again, option option dot something or instance specific. And this dot per instance, comment dot auto Bane and auto dot weight are exactly the same that I explained in this previous slide. So there are a lot more options available both instance specific and cover group type. I've not going through the detail of each one of those they are very exhaustive list, please refer to the LRM for for reading through all the different options available to you to manage your project even better.
Well, that's all folks. This was a brief but in depth introduction to functional coverage, hope it has been of help to you. I wish you the best in your project. And make sure you do functionally cover everything. Thank you