Rent's rule is a heuristic used in VLSI design to predict the wiring complexity and pin count of a microprocessor or ASIC. It states that the number of input/output pins scales exponentially with the number of internal logic gates. Chip architects use this rule to estimate packaging requirements, route density, and thermal dissipation before laying out the physical silicon.
We're hitting the limits of Rent's rule on this package, so we need to multiplex the data bus to save pins.
Related terms
VLSI
Very large-scale integration is the process of creating an integrated circuit by combining thousands to millions of transistors onto a single chip.
ASIC
An application-specific integrated circuit designed for one dedicated task rather than general-purpose use.
Pinout
A diagram or table detailing the purpose of each electrical contact on a connector or chip.