Controlled toggle rate of non-test signals during modular scan testing of an integrated circuit
AssigneesCadence Design Systems, Inc., Imec
InventorsErik Jan Marinissen, Sergej Deutsch
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Abstract
A method is provided to test a modular integrated circuit (IC) comprising: testing a module-under-test (MUT) within the IC while causing a controlled toggle rate within a first neighbor module of the MUT; wherein the controlled toggle rate within the first neighbor module is selected so that toggling within the first neighbor module has substantially the same effect upon operation of the MUT that operation of the first neighbor module would have during actual normal functional operation of the first neighbor module.
Claims32
A method to test a modular integrated circuit (IC) comprising:
- identifying a plurality of neighbor modules that neighbor a module-under-test (MUT) within the IC;
- selecting a controlled toggle rate for a first neighbor module of the plurality of neighbor modules, wherein the controlled toggle rate represents a number of toggles of a plurality of state elements of the first neighbor module during a time interval;
- generating a toggle pattern within the first neighbor module to cause a controlled toggle rate switching within the first neighbor module to affect testing of the MUT;
- and
- testing the MUT within the IC while switching the first neighbor module at the controlled toggle rate.
The method of claim I, wherein the controlled toggle rate within the first neighbor module is selected so that toggling within the first neighbor module has substantially the same effect upon operation of the MUT that operation of the first neighbor module would have during actual normal functional operation of the first neighbor module.
A modular integrated circuit comprising:
- a first module that includes a first scan chain, a scan-in port, a toggle generator and a first switch coupled to selectably couple one of (i) the scan-in port to a scan input of the first scan chain during scan mode operation of the first module, or (ii) a toggle generator output to a scan input of the first scan chain during scan mode operation of a second module to cause a controlled toggle rate switching in the first module during testing of the second module.
A modular integrated circuit comprising:
- a first module that includes a first scan chain;
- and
- a second module that is a neighbor of the first module and that includes:
- one or more second scan chains,
- a toggle generator, and
- an input switch coupled to the one or more second scan chains to selectably couple one of (i) the toggle generator to a scan input of the one or more second scan chains during scan mode operation of the first module, or (ii) a scan-in port to the scan input of the one or more second scan chains during scan mode operation of the second module;
- wherein the toggle generator includes a loop back shift register that is configured with state values to impart toggles to the one or more second scan chains in a pattern to cause scan cells of the one or more second scan chains to toggle at a toggle rate that causes controlled switching effects upon the first module during scan mode operation of the first module.
An integrated circuit comprising:
- a pluralitv of modules, comprising:
- a module-under-test MUT) of the plurality of modules:
- a neighbor module of the plurality of modules that includes a toggle generator and a plurality of state elements, wherein the neighbor module neighbors the MUT;
- wherein the toggle generator is configured to impart a toggle pattern to the plurality of state elements to cause toggling within the neighbor module at a controlled toggle rate during testing of the MUT;
- and
- wherein the controlled rate of toggling within the neighbor module is selected so that toggling within the neighbor module has substantially the same effect upon operation of the MUT during testing that operation of the neighbor module is expected to have during actual normal functional operation of the first neighbor module.
Dependencies are inferred from the claim text.