Functional_coverage

UVM
,
1

hi,

i am verifying spi in uvm environment using questa sim ...

when i am checking functional coverage of 1st test case it is showing …

Coverage Summary by Structure:Design Scope ◂ Coverage (%) ◂
spi_pkg 79.92%
ctrl_seq 100.00%
data_seq 100.00%
divider_seq 100.00%
ss_seq 100.00%
gobusy_seq 100.00%
read_seq 100.00%
simple_response_seq 100.00%
my_scoreboard 59.84%

when i am merging all test cases then it shows merged all cases but functional coverage % remains same…

Coverage Summary by Structure:Design Scope ◂ Coverage (%) ◂
spi_pkg 79.92%
ctrl_seq 100.00%
ctrl_seq1 100.00%
ctrl_seq2 100.00%
data_seq 100.00%
data_seq1 100.00%
divider_seq 100.00%
divider_seq1 100.00%
divider_seq2 100.00%
divider_seq3 100.00%
divider_seq4 100.00%
divider_seq5 100.00%
divider_seq6 100.00%
divider_seq7 100.00%
divider_seq8 100.00%
divider_seq9 100.00%
divider_seq10 100.00%
divider_seq11 100.00%
ss_seq 100.00%
ss_seq1 100.00%
gobusy_seq 100.00%
gobusy_seq1 100.00%
gobusy_seq2 100.00%
read_seq 100.00%
read_seq1 100.00%
simple_response_seq 100.00%
my_scoreboard 59.84%

regards
Raghu

2

In reply to raghu_singh:

Hi Raghu,

      I am also  doing spi verification. Bt i dont know about coverage.Can u send me the coverage code? at 1117ashish@gmail.com.

Thanks and Regards
Ashish

3

In reply to 1117ashish:

hi ashish,

        i am sending the coverage code like that u can make better coverage ....u can add more signals and bins, cross...

covergroup cg;

address: coverpoint trans.wb_adr_i{

bins ctrl_reg={16};
bins data_reg={0,4,8,12};
bins div_reg={20};
bins ss_reg={24};
}

least_sign_bit: coverpoint trans.lsb;

write_enable: coverpoint trans.wb_we_i{

bins we_value[2]={0,1};
}

tx_negative: coverpoint trans.tx_neg{

bins tx_neg_value={0,1};
}

go_busy: coverpoint trans.go_bsy;

c1: cross least_sign_bit,tx_negative;

c2: cross least_sign_bit,write_enable;

endgroup

regards
Raghu

4

What is your question? It is possible that your coverage model isn’t sufficient enough or that all of your tests result in the same functional coverage. If this is the case, when you merge all of your tests, you will see no difference in total coverage.

You can use Questa to rank your tests to determine their effectiveness. If you only have one test that contributes and the others duplicate the same coverage, the ranking report will identify this.

5

In reply to raghu_singh:

Thnaks a lot Raghu.

6

In reply to cgales:

hi cgales,

        thanks for reply...

i got my answer … every time i was getting the same result due to duplicate result for all test cases…the value of signals were not updating in the coverage report so all the test cases give same result and after merging also it was giving same % …

Regards
Raghu

7

In reply to raghu_singh:

Hi raghu

How did you rectify ? Even I am facing the same issue. My coverage report is not updating. Can you suggest please

Regards

Srikanth