randc kind of implementation in e

When I went through SystemVerilog constructs, one of the unique construct I found out was randc. Cyclic randomization sometimes helps you generating all unique combinations before repeating it. One classic usage example of randc is to inject all the sequences into DUT at least once without repeating it again. So, I was wondering if it is possible to implement it in e. I realized that though you can not generate the item based on its previously generated values, you can have some workaround for that using list psudo methods. There are all_values() and is_a_permutation() psudo methods which can be used for this purpose.

Let me explain the logic to implement that classic usage example to inject all the sequences into DUT without repeating it. If we somehow generate a list of unique sequence kinds randomly, we can take that list items one-by-one and generate the sequence based on that kind. So, to generate the unique yet random list of sequence kind, we can use above mentioned two list psudo methods. Take a look at the following code snippet.

<'

type seq_type_t : [SEQ_A, SEQ_B, SEQ_C, SEQ_D, SEQ_E, SEQ_F, SEQ_G];

extend MAIN my_sequence_s

{

seq_randc : list of seq_type_t;

keep seq_randc.is_a_permutation(all_values(seq_type_t));

!seq : my_sequence_s;

body() @driver.clock is only

{

gen_seq_randc();

for i from 0 to seq_randc.size() - 1

{

do seq { keeping .kind == seq_randc[i]; }

};

};

};

'>

all_values(seq_type_t) statement will return a list which will have all the unique values of scaler type seq_type_t. is_a_permutation() will make sure that seq_ranc list has random but all the fields of the list returned by all_values(seq_type_t) statement. Thus, we have a list which has all the random values of the sequence kind. Now, we can loop through this list one by one and generate a seq and push it to the DUT.