Replication Patterns

I'm assuming that PREAMBLE_SIZE is a parameter. In that case, you could try to add another set of brackets like


parameter PREAMBLE_SIZE=16;
...
preamble = '{{PREAMBLE_SIZE{40'hDDDDDDDDDD}};
....

David Walker

PREAMBLE_SIZE is an input to the "new" function and is used to set the size of the dynamic array.

When I added the extra brackets I get an error that says "Illegal operand for constant expression" which sounds closer than I was before. 

I need to figure out how to tell SV that the function input is a constant, I guess.

Hm, I tried "const ref" and "const ref int" and both give me the same error message:

"Illegal operand for constant expression"

Does anyone have any ideas?

What I have is a transaction with resizeable preamble, data, and flush fields so I want to set them in the new() function and use dynamic arrays to hold the parts.

replication patterns are not currently supported, something like the following works in 5.8. not the most elegant, but the underlying implementation would need to do the same....

module temp;

parameter PREAMBLE_SIZE = 16;
bit preamble[];

initial
begin
preamble=new[PREAMBLE_SIZE];
for (int i=0; i preamble[i]=40'hDDDDDDDDDD;
end

endmodule

If it's a parameter, why not do

------------------------------------
module temp;

parameter PREAMBLE_SIZE = 16;
bit [PREAMBLE_SIZE*40-1:0] preamble;

initial begin
preamble='{{PREAMBLE_SIZE{40'hDDDDDDDDDD}}};
end

endmodule
------------------------------------
It compiled for me in 5.83. I assume the OP wanted to pass it to a task as a parameter like

------------------------------------
module test;

// the dynamic array must be defined here because it is invalid in a task
bit preamble[];

task xxx(input int PREAMBLE_SIZE);


preamble = new[PREAMBLE_SIZE*40];

preamble = '{PREAMBLE_SIZE{40'hDDDDDDDDDD}};

endtask

initial begin
xxx(13);
xxx(10);
end

endmodule
------------------------------------

When I did this, I got the same error messages as the OP. I tried your for loop trick in the above and it worked OK.

David Walker

yeah, my bad. The issue is with replication initialization which is not currently supported. ~jm