Algorithmic comparator (Scoreboard) in UVM is a useful utility to compare two different streams of transactions. Different types of transaction class can be compared with this scoreboard. Algorithmic comparator takes three parameters BEFORE, AFTER and TRANSFORMER. The TRANSFORMER class is the one that transforms one stream of transaction to other. TRANSFORMER class should implement a transform function with the following prototype
function AFTER transform ( BEFORE b )
Transform function should implement how transaction class BEFORE is converted to AFTER and return the converted transaction object.
Matches and Mismatches in this scoreboard is reported in terms of the AFTER transactions.