Text - KFUPM - King Fahd University of Petroleum and Minerals

In Selective Low Care (SLC) scheme [87], the linear dependencies of the internal
scan chains are explored, and instead of encoding all the specified bits in test cubes,
only a smaller amount of specified bits are selected for encoding. It employs a Fanout
Compression Scan Architecture (FCSCAN) [88], the basic idea of which is to
target the minority specified bits (either a 1 or 0) in scan slices for compression.
A compression scheme using reconfigurable linear decompressor has been proposed
[89]. A symbolic Gaussian elimination method to solve a constrained Boolean
matrix is proposed and utilized for designing the reconfigurable network. The proposed
scheme can be implemented in conjunction with any decompressor that has
a combinational linear network. In a scheme based on periodically alterable MUXs
[90], MUXs-based decompressor has multiple configurations to decode the input
information. The connection relations between the external scan-in pins and the
internal scan chains can be altered periodically. The periodic reconfiguration of the
mapping between the scan-in pins and the internal scan chains is done by changing
the control signals of the MUXs decompressor. Only a single input is required to
change the configurations. The scheme uses tailored ATPG along with a two-pass
patterns compaction. The scheme proposed in this work also uses idea of configurations
of MUXs to decompress groups of scan chains.
Schemes utilizing arithmetic structures include a reconfigurable serial multiplier
based scheme [91] in which test vectors are stored on the tester in a compressed
format by expressing each test vector as a product of two numbers. While performing
24