Scannable memory array and a method for scanning memory

Abstract

An array of memory cells includes a scan chain with one or more chain segments of storage memory cells. Chain segments are separated by chain buffer memory cells. Memory cells of each chain segment are coupled with a sequence generator that generates a sequence of non-overlapping pulses from a pulse in a scan clock (SCLK) signal. The duration of the sequence equals at most a cycle of the SCLK signal. The scan chain applies the pulses to the memory cells backwards starting from the chain buffer memory cell. Memory cells may include a single latch. The array of memory cells may be included in a semiconductor memory subsystem. A scan chain that has a fault condition may be repaired by rerouting the scan chain to avoid the location of the fault condition and to add one or more redundant chain segments.