Course : Systemverilog Verification 5 : L10.1 : Coverage Options

[00:00:00]coverage options in systematic so this was the general structure of a cover group definition that you have learned in the first session and there is a way to specify different options to this cover group and in this session you are going to learn what all are the options that you can specify with the curve group definition to give a cover group option you will use keyword option and followed by a doubt you should you will give the option name and the options can be specified in below levels you can specify an option in a cover group or in a cover point or in a cross cover point or with an instance that is created so when you create or specify an option in a cover group then these options will be applied to all the cow points and cross power points listed in that cow group and when you specify an option within a cow point or within a cross cover point then those options will be applied only to those cover point and you can change this option specified within the powerpoint when you create an instance of the car point then those options will be instant specific options will be overridden with the new options given with the instance now you are going to learn these options in detail in the next session in this slide you will see a few options that is available in system airlock for coverage definition and the next slide will list down all the options available so we will see few options in detail the first one is the comment so you can add any comment to a cover group report to make it easy to analyze uh using the option option.comment so when you give a comment to that option those particular comments will be appearing in the coverage report you can so that you can easily analyze them it's better to give the comments relating to the verification plan of this powerpoint and next option is instant specific coverage in order to enable instant specific coverage you can use the option option dot ins for instance you know that after defining a cover group you have to create an instance of instant of that group in order to make them appear or in order to count them in the final coverage data so assume that you are creating multiple instances of the saving group for a different reason so if your test punch instantiate a cover group multiple times then by default system will lock groups together all the coverage data from all these instances so you cannot differentiate these uh covered coverage data per instance in the final report so if you wanted to analyze them per instance then use this option or set this options to one and this option keep track of the coverage for each instance of the report and next one is coverage threshold so option dot at least will set the threshold of this coverage so its default value is uh set to one so it is saying how many times this particular coverage uh should or this particular cow group should get hit so you know that every cow group on our cover point should get hit at least once so it set to default value one this option will be useful when you do under visibility to the design code when you cannot access the individual variables in the design code this option can be used to make sure that this particular power point hit at least n times which will ensure some other events in the design for example consider a state machine assume that you don't have access to the variable which is specifying the state of the state machine but you want to make sure that a particular state is being hit if you know that the input signal or the output signal is coming in or repeated by or some cover group a coupon definition is hit for n time so for 10 time then this state will definitely hit so in this situation you can use the option option dot at least and next one is printing the md bins you can for that you can use the option option dot cross num print missing so by default the coverage report shows only the bins which are sampled so this option can be used uh to tell the simulation and report tools to show the options which are not hit within the simulation next is option gold and by default your aim is to get hundred percent uh 100 percent coverage for this particular group defined but in in some situation if you want to change the goal from 100 to some other lower value you can use this goal which is specifying the final goal in percentage and this is not a recommended practice to change the goal from 100 percentage now we will see an example here so this same cover group named best values which is sampled at every positive object clock now for this entire curve group i have listed three options like option dot comment per instance and gold so these three options will be applied to all the curve points defined in this curve group which are adida range data range and this cross coverage also some options are given only specific to the cover point so here the copper named led range the gold is set to 50 percent for this cow point and in this cross coverage i have given the name i given the option cross num print missing as 500 which will print the 500 missing cross coverage points thus you can specify the options either at the group name which will cover group level which will apply the of all these options to all the powerpoints or at cover point level which is specific to that particular coupon now you know that always you have to create the instance of the group and you have to know them using the constructor in order to count that call group in the final coverage data so ideally you will create the instance in in some procedural block like initial begin here i have created the instance of the group named best values uh with the instance name b underscore cover underscore 1 and you should always new it using the new constructor and if there is any argument you should pass that while creating the instance of the group now these are the options that is specified in the cover group definition and you can change this options only for this particular instance by using the option keyword so this is the for syntax you will use the instance name dot option dot the option name and you will give the volume so this will change the comment for all the coverage points within this group instance name b underscore counter score one and also you can change uh the cover point specific options within an instance so it's like its format is like the instant name dot com point name dot option dot the option value thus you have learned the usage of the option within a cover group or a cover point or a cross curve or within an instance of a cow point here you have learned only a few options available and the next slide is summarizing all the options available in system will look so these are the instant specific coverage options available first one is weight this you have already learned when you learn the cross coverage definition and next one is gold this is also learned in the previous slide and third one is name this is an optional name that you can give for us coverage group and comment you had already seen in the last session and at least also you have seen and detect overlap if you set this to one then a warning is issued if there is an overlap between the list range in the coverage bins and also auto bin max you have already seen in the initial sessions and cross coverage auto inbox is the same it's similar to the auto inbox and it's it's useful for the cross coverage definition and cross numb print missing is used to print the missing power points and this you hardly see in the previous session and per instance also you have seen right now this table summarizes whether these options can be used within the cover group definition or in a coupon definition or in a cross coverage definition so here you can see these all these options can be used for for the car group and within the component you cannot use the option called name cross autobin max or cross name is print missing or per instance and within the cross coverage point definition you cannot use the name option or the detector overlap option or the auto bin max option or the per instance option these are the instant specific coverage options in system reload and in system verilog there is another type of coverage options which are static in behavior and you will learn them in the next session