Creating cross-coveraghe within vr_ad

Hi Maurizio,

Normally what I would do is grab the field value from its enclosing reference model by method or by pointing to it.
This way I can cross reg values with other reg values or with any info I need in the data path. The advantage here is that the sampling event is already taken care of.
I believe you could also extend the reg_file struct and define the cross items there, but then you'll have to take care of the sampling event, and make sure coverage is only recorded when relevant.

I hope that helps...

Yaron

Hi Maurizio,

If the registers are part of the same register file (group, map), then you should probably add the cross between XX_a and YY_b at the group level (I would not add it inside XX or YY though). The sampling event for the register file would be the same for XX and YY, but I would still define it as:

event reg_file_access is @XX.reg_access or @YY.reg_access;

If the registers are NOT part of the same register file, then they could be updated at different times and hence you need to

a) Select an appropriate container/observer (the agent would probably be best)

b) Define a sampling event:
    event reg_file_access is @my_reg_file1.XX.reg_access or @my_reg_file2.YY.reg_access;

The good thing about defining these events is that they make it easy to do coverage per unit instance.

You can also take a look at ${IPCM}/util_lib/vr_ad/examples/vr_ad_reg_cover.e for some other interesting examples. 

Hope this helps,

 -Stelix.