Verifying dynamic memory refresh

摘要

A dynamic memory having self refreshing capability performed without external strobing, is interruptable and can be strobed to initiate a refresh cycle for testing interrupt response timing. In operation of such a dynamic memory, interruption of a self refresh cycle precedes initiation of a read or write cycle by a time tRPS, sufficient for row precharge. Although tRPS can be estimated based on worst case analysis, lower tRPS characteristics can be guaranteed, resulting in higher yields, by measuring tRPS during memory fabrication using circuits and methods disclosed. In an alternate embodiment, output of a signal indicative of the beginning of a refresh cycle is enabled by a test signal.