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Hi David,

Thanks for nice post, it is quite useful.

I have a few comments:
1. If we want fewer lines of the code, we can combine Bins using concatenation &, for example :

— Test21
FSM_CP.AddCross(“Test21”, GenBin(BlackJack_type’POS(Test21)),
GenBin(BlackJack_type’POS(BustState)) & GenBin(BlackJack_type’POS(HoldState)) & GenBin(BlackJack_type’POS(TenBack)));

2. As an alternative to the approach in the post,
it is good idea to separate the coverage model and the coverage collector in two processes:

COVERAGE_MODEL: process
begin
— Begin_g
FSM_CP.AddCross(“Begin_g to Hit_me”,
GenBin(BlackJack_type’POS(Begin_g)),
GenBin(BlackJack_type’POS(H1_Hit_me)));
.
.
.
— Mark rest as illegal.
FSM_CP.AddCross(ALL_ILLEGAL, ALL_ILLEGAL);
wait;

end process COVERAGE_MODEL;

COVERAGE_COLLECTOR: process
constant COMBINATIONAL_DELAY : time := 1 ns;
alias current_state is <>;
alias next_state is <>;
begin

wait until rising_edge(clk);
wait for COMBINATIONAL_DELAY;
— update coverage information
v_fsm_transition_coverage.ICover( (BlackJack_type’POS(current_state), BlackJack_type’POS(next_state)) );

end process COVERAGE_COLLECTOR;

Regarding the external names used in COVERAGE_COLLECTOR process, it is assumed that RTL code of the FSM contains the process for FSM state register.
Something as:

STATE_REG: process(clk, reset_n)
begin
if reset_n = ‘0’ then
current_state <= Begin_g;
elsif rising_edge(clk) then
current_state <= next_state;
end if;
end process STATE_REG;

Best regards,
Miroslav

Hi Miroslav,
Thank you for your kind comments and encouragement, I am glad my post was helpful, hopefully you will find my upcoming post useful as well.
With regards to your questions:
1. Could you use concatenation to shorten the code? Probably, I haven’t tried it. Typically I tend to write things out longhand so to speak, as you see here each stage is clearly separated. This helps with understandability and maintainability.
2. Using two processes once for the coverage model and another for the coverage collector, the important thing is to ensure all the collection bins are built at time zero, this happens when the process gets evaluated at time zero (All process run to their first wait). I am not sure of the benefit of splitting the coverage model into two parts.Maybe I will discuss this with Jim next time we speak

Keep safe
David…