Associative array find_index method
SystemVerilog array Index finder method shall return single or multiple indexes which satisfies the condition.The condition also shall be single or multiple conditions. multiple conditions can be written on using conditional expressions. example: &&, || etc.
一、index finder methods
- find_index() returns the indexes of all the elements satisfying the given expression
- find_first_index() returns the index of the first element satisfying the given expression
- find_last_index() returns the index of the last element satisfying the given expression
- unique_index() returns the indexes of all elements with unique values or whose expression is unique‘with’ clause is optional for min,max,unique and unique_index methods
二、associative array find_index example
Below example shows the return of single and multiple index return.
class packet;
int a;
int b;
function void display();
$display("\tValue of a = %0d",a);
$display("\tValue of b = %0d",b);
endfunction
endclass
module assoc_array;
//declaration of array
packet assoc_array[*];
packet pkt;
int count,qu[$],tmp_var;
initial begin
pkt = new();
pkt.a = 8;
pkt.b = 3;
assoc_array[2] = pkt;
pkt = new();
pkt.a = 0;
pkt.b = 6;
assoc_array[5] = pkt;
pkt = new();
pkt.a = 2;
pkt.b = 6;
assoc_array[6] = pkt;
pkt = new();
pkt.a = 1;
pkt.b = 6;
assoc_array[9] = pkt;
//----------------------------------------------------------------------------
//------- Find Index Method -------
//----------------------------------------------------------------------------
//Type-1: returning one matching index
qu = assoc_array.find_index with (item.a == 'h2);
count = qu.size();
for(int i=0;i<count;i++) begin //{
tmp_var = qu.pop_front();
$display("Index of Asoc Array for a == 2 is %0d",tmp_var);
end //}
//Type-2: returning mutiple matching index
qu = assoc_array.find_index with (item.b == 6);
count = qu.size();
for(int i=0;i<count;i++) begin //{
tmp_var = qu.pop_front();
$display("Index of Asoc Array for b == 6 is %0d",tmp_var);
end //}
//Type-3: with multiple conditions
qu = assoc_array.find_index with (item.a == 2 && item.b == 6);
count = qu.size();
for(int i=0;i<count;i++) begin //{
tmp_var = qu.pop_front();
$display("Index of Asoc Array for a == 2, b == 6 is %0d",tmp_var);
end //}
//Type-4: with multiple conditions
qu = assoc_array.find_index with (item.a < 2 && item.b > 5);
count = qu.size();
for(int i=0;i<count;i++) begin //{
tmp_var = qu.pop_front();
$display("Index of Asoc Array for a < 2, b > 5 is %0d",tmp_var);
end //}
end
endmodule
- Simulator Output
Index of Asoc Array for a == 2 is 6
Index of Asoc Array for b == 6 is 5
Index of Asoc Array for b == 6 is 6
Index of Asoc Array for b == 6 is 9
Index of Asoc Array for a == 2, b == 6 is 6
Index of Asoc Array for a < 2, b > 5 is 5
Index of Asoc Array for a < 2, b > 5 is 9