Techniques for characterizing DRAMs with a 500 MHz interface

The advent of high-bandwidth DRAMs poses a number of new challenges for test and characterization. This paper describes a collection of techniques that were used in the design and characterization of a new DRAM architecture with 500 MHz I/O signals. Methods of fixturing and calibration are presented for achieving system accuracies of better than 100 ps. Laboratory techniques for measuring critical circuit parameters such as path delay, clock jitter, current source strength, and pin capacitances are shown as well. These techniques, along with on-chip test logic, which allows the DRAM core to be tested using conventional low-speed memory test equipment, enable full characterization of high bandwidth memories.