Scan-load-based dynamic scan configuration

Abstract

A scan-load-based (SLB) dynamic scan configuration reconfigures scan structures via scan-load operation, thereby eliminating interconnect network distributing configuration signals, and employs common scan circuitry identical for designs at mask level and is suitable for ASIC implementations. The architecture includes reconfigurable scan cells, apparatus for distributing configuration data to the reconfigurable scan cells and for determining desired reconfiguration data for each of the reconfigurable scan cells, and a configuration-set (CS) signal. Each of the reconfigurable scan cells has a pass-through (PT) mode in which data input, either a scan-in (SI) or a system-data (SD) of the scan cell, is transparently passed to a scan-out (SO) terminal of the scan cell without requiring a pulse on a shift clock (SC). The configuration-set (CS) signal communicates with each of the reconfigurable scan cells. A pulse on the configuration-set (CS) signal triggers PT Hold latches to capture configuration data from corresponding slave latches, which in turn set configurations of each of the reconfigurable scan cells.