Method for abstraction of manufacturing test access and control ports to support automated RTL manufacturing test insertion flow for reusable modules
A system for RTL test insertion in an integrated circuit layout pattern includes a core module, a test wrapper, and a smart wrapper. The core module describes a function defined by logical elements, interconnections between logical elements, input pins and output pins. The test wrapper is adapted to encapsulate the core module and to create test pins representing the core module. The smart wrapper is adapted to encapsulate the test wrapper and to assign the test pins to a non-asserted state. The smart wrapper is adapted to place an assertion on one or more of the test pins for static or dynamic testing of the integrated circuit layout pattern.
1. A system for RTL test insertion in an integrated circuit layout pattern, the system comprising:
a core module describing a function defined by logical elements, interconnections between logical elements, input pins and output pins;
a test wrapper, which encapsulates the core module, comprises input pins and output pins corresponding to the input pins and output pins of the core module, and creates test pins for the core module regardless of whether the core module includes test structures with corresponding test pins; and
a smart wrapper, which encapsulates the test wrapper and comprises input pins and output pins corresponding to the input pins and output pins of the test wrapper, wherein the smart wrapper hides the test pins and assigns the test pins to a non-asserted state, wherein the smart wrapper places an assertion on one or more of the test pins for static or dynamic testing of the integrated circuit layout pattern.
2. The system of claim 1 wherein the test wrapper and the smart wrapper comprise computer readable blocks of RTL code.
3. The system of claim 1 further comprising:
chip-level test resources coupled to gate-level test structures of the core module that are swapped in at the gate-level for the RTL-level test pins of test wrapper.
4. The system of claim 1 wherein the core module comprises gate-level test structures, and wherein the test pins of the test wrapper correspond to pins of the gate-level test structures.
5. The system of claim 1 wherein the core module comprises a placed and routed macro, and wherein the test wrapper represents test structures to a design tool for the core module that does not include test structures.
6. A system for test insertion within an integrated circuit layout pattern, the system comprising:
a core module describing a function defined by logical elements, interconnections between logical elements, input pins and output pins, the core module defining a test structure with module test pins;
an RTL test wrapper, which encapsulates the core module, comprises input pins and output pins corresponding to the input pins and output pins of the core module, and creates test pins coupled to the module test pins; and
an RTL smart wrapper, which comprises input and output pins corresponding to the input pins and output pins of the RTL test wrapper, wherein the RTL smart wrapper ties off and hides test pins of the RTL test wrapper.
7. The system of claim 6 wherein the integrated circuit layout pattern comprises gate-level test resources, and wherein the test structure of the core module is coupled to the gate-level test resources through the smart wrapper by the test pins.
8. The system of claim 6 wherein the smart wrapper further comprises:
assertions, which assign at least one of a value or an expectation of the value to one or more test pins.
9. The system of claim 8 wherein the smart wrapper assigns the value to an input test pin for static formal model checking of the core module after test hookups are made to global test resources.
10. The system of claim 8 wherein the smart wrapper assigns the value to an input test pin for dynamic assertion-based verification of the core module.
11. The system of claim 8 wherein a change to the value during functional simulations is indicative of improper use of the test pin.
12. The system of claim 6 wherein the test pins of the test wrapper are tied to a non-asserted state by the smart wrapper.
13. A system for test insertion in an integrated circuit layout pattern, the system comprising:
a core module describing a function defined by logical elements, interconnections between logical elements, input pins and output pins;
a test wrapper, which encapsulates the core module comprises input pins and output pins corresponding to the input pins and output pins of the core module, and creates test pins representing test structures of the core module; and
a smart wrapper, which encapsulates the test wrapper, comprises input and output pins corresponding to the input pins and output pins of the RTL test wrapper, and assigns the test pins to a non-asserted state, and wherein the smart wrapper hides the test pins.
14. The system of claim 13 wherein the integrated circuit layout pattern comprises chip level test resources and wherein the core module is coupled to the chip level test resources though the smart wrapper by the test pins.
15. The system of claim 13 wherein the smart wrapper further comprises:
assertions placed on one or more test pins of the core module.
16. The system of claim 15 wherein the assertions comprise values for checking test pin connections statically through formal verification techniques.
17. The system of claim 13 wherein the non-asserted state comprises a value selected such that test structures of the core module are not activated.
18. The system of claim 13 wherein the core module comprises:
a core test structure;
core test input pins coupled to the core test structure, which receive a test input; and
core test output pins coupled to the core test structure, which deliver a test output from the core test structure;
wherein the core test input pins and the core test output pins are coupled to the test pins of the test wrapper at an RTL level.
19. The system of claim 13 wherein the core module, the test wrapper, and the smart wrapper comprise computer readable RTL code.