Cross coverage with ignore_bins that consists of autobins

SystemVerilog
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1

Hi,

Does it work if I ignore some portions of the cross coverage that consists of coverpoint that has autobins?
Original example (work fine):

a_cp: coverpoint a { a_bin = {[1:10]}; }
b_cp: coverpoint b { b_bin[5] = {[11:15]}; }
c_cp: coverpoint c { lo = {16}; med = {17}; hi = {18}; }
abc: cross a, b, c {
ignore_bins a0_b1_clo = (binsof(a) intersect {1}) && (binsof(b) intersect {12}) && binsof(c.lo); }

Once i change the last line to this:
ignore_bins a0_b1_clo = binsof(a.a_bin[0]) && binsof(b.b_bin[1]) && binsof(c.lo); }
Simulator flags error.

My I know why? The autobins cannot be represented in binsof()?

Thank you.

2

You are not allowed to access bins by an index because the index numbering is not defined by the standard. You can only see it in reports. Also, the setting of auto_bin_max will effect which values are part of a bin element. Using (binsof(a) intersect {1}) guarantees you only cross the bin associated with the value 1. The tool may have named the first bin with the index 1, not 0.

3

Got it, thank you Dave!