Method and configuration for protecting data during a self-test of a microcontroller
AssigneeInfineon Technologies AG
InventorsMichael Richter, Jan Otterstedt
Life of this patent
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Abstract
The invention relates to a method for protecting data during a self-test of a microcontrollers, in which all of the circuit elements within the microcontroller can be tested, where the course of the self-test cannot be altered via the external pins, and no intermediate results are passed to the outside via the pins. The invention also relates to an configuration in the form of an integrated circuit which can be used to implement the method, and to correspondingly equipped microcontrollers.
Claims35
A method for protecting data while self testing a microcontroller and testing circuit elements within the microcontroller, a course of the self-test not being alterable via an external pin, and no intermediate results being passed to the outside, which comprises the steps of:
- providing the microcontroller with a boundary scan having registers;
- storing a built-in self test (BIST) in the microcontroller;
- and
- generating test patterns within the microcontroller with the BIST by using the registers of the boundary scan.
An integrated circuit configuration for protecting data during a self-test, comprising:
- a microcontroller storing a boundary scan having registers, said microcontroller generating test patterns with the test program by using said registers of said boundary scan;
- devices for starting the self-test and for performing the self-test internally, the self-test covering all fundamental elements of said microcontroller, and for outputting a corresponding test response;
- devices for storing a self-test program;
- and
- devices for isolating external input and output devices from the devices for performing the self-test throughout execution of the self-test.
A microcontroller, comprising devices for conducting a data-protecting self-test for testing circuit elements within the microcontroller, a course of the self-test not being altered via an external pin, and no intermediate results being passed to the outside;
- said devices providing a boundary scan having registers, storing a built-in self test (BIST) program, and generating test patterns with the BIST by using the registers of the boundary scan.
Dependencies are inferred from the claim text.