Automatic delay calibration method for multi-channel CMOS formatter

This work describes the technique used for automatically calibrating vernier delay steps in Credence CMOS formatter-RIC/DICMOS. Embedded within the timing generation IC, RIC/DICMOS provides formatted levels and internal strobe markers for eight independent pin-electronics channels at up to 800 Mbps with +/-81 ps accuracy. Utilizing the on-chip, run-time auto-calibration circuit, all eight RIC/DICMOS vernier channels can be calibrated in parallel nearly 500 times faster than the prior generation formatters. Furthermore, the same calibration circuit can also provide 16-bit time-period or frequency counts for up to eight independent off-chip signals.