Simplify the following text for a Grade 13 native English-speaking person.
Original: The replication of functional units was only made possible when the integrated circuit ( some times called `` die '' ) area of a single-issue processor no longer stretched the limits of what could be reliably manufactured .
Simplified: The replication of functional units was only made possible when the die area of a single-issue processor no longer stretched the limits of what could be reliably manufactured .