- The Intel 386 processor used standard cell logic to automate chip layout, allowing it to finish ahead of schedule despite having 285,000 transistors.
- Standard cells are pre-designed circuits (e.g., inverters, NAND gates) that are placed and routed by software, speeding up design but risking density issues.
- The 386's register control logic employs large multiplexers built from CMOS switches (transmission gates) rather than AND/OR gates for efficiency.
- A single misplaced PMOS transistor was found between standard cell columns, likely a manual bug fix to avoid costly re-layout.
- Some cells that appear as inverters are actually independent NMOS and PMOS transistors with separate inputs, used as additional multiplexer cases.
- The success of standard cell logic in the 386 was a risky but pivotal decision, advancing the x86 architecture to 32-bit dominance.