AC IO loopback design for high speed /spl mu/processor IO test

This work presents the next generation AC IO loopback design for two Intel processor architectures. Both designs detect I/O defects with 20 ps resolution and 50 ps jitter for up to 800 MHz bus speed. Even though the implementations differ in some aspects to accommodate two different bus architectures, the same prudent considerations for high speed operation, minimum test inaccuracy, and low implementation costs apply to both.