Cost-Effective High-Speed DRAM Testing: Circuit-Level Enhancements with Clock Multiplication and ECC

High-speed advanced dynamic random access memory (DRAM) interfaces can exceed 6400 Mbps, placing a significant financial burden on test environments that rely on equivalently high-speed probe cards. This study proposes a method that uses clock multiplication and error correction code (ECC) bypass to enable high-speed testing, even with a more cost-effective, lower-speed probe card. By bypassing the dividing stage in the internally generated delay-locked loop (DLL), the internal clock is effectively multiplied, allowing the DRAM to operate at twice the external clock rate, despite the lower frequency input of the probe card. Furthermore, there is no need to double the read time when retrieving data. The test can be completed simply by adding the time required to read the ECC data. Consequently, the overall test time can be reduced to approximately 62.5 percent of the typical time required in a conventional read scheme. Experiments conducted under a range of voltage conditions confirm that this method effectively detects internal DRAM defects, even when the external operating environment uses a lower frequency.