The invention discloses a multi-core
cascade EDT scanning test circuit and a test method, and relates to the field of
integrated circuit test and
testability design. In order to improve the multi-core
chip test efficiency and reduce the test cost, the invention provides a cascaded EDT scanning test circuit which comprises a plurality of EDT compression interface modules which are sequentially connected in series, and each module wraps a core to be tested; the serial EDT control module is used for uniformly controlling
test data decompression, signature compression, bypass and
mask updating operation of each core; the EDT modules are in
cascade connection through a
data channel with a fixed bit width to form a cross-core scanning path. According to the scheme, the EDTs of the multiple to-be-tested cores with the same compressed data bit width and the scanning chains in the cores can be connected in series, the test
operation mode is similar to the mode that the scanning chains are used for mounting the multiple to-be-tested cores without the EDTs in series, and the test
operation mode is compatible with an existing JTAG interface
time sequence. The scheme supports dynamic bypass and
mask configuration, is simple in circuit, can be used as an independent test scheme, can also be embedded into an existing SSN test architecture to reduce the number of SSH nodes and configuration overhead, and is suitable for multi-IP core
chip scanning test.