Test access control for secure integrated circuits
First Claim
Patent Images
1. An integrated circuit comprising:
- a test circuit configured to perform test operations upon at least a portion of said integrated circuit; and
a test rights controller configured to receive and authenticate a test access request;
whereinif a received test access request passes authentication by said test rights controller, then said test rights controller is configured to permit said test circuit to perform a level of test operations corresponding to said received test access request; and
if said received test access request does not pass authentication by said test rights controller, then said test rights controller is operable to prevent said test circuit performing test operations, wherein said test access request includes a test rights enabling key and said test rights controller comprises;
an interface circuit configured to read said test rights enabling key from an external data storage device; and
a key authenticator configured to authenticate said test rights enabling key read from said external data storage device.
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Abstract
Test access to an integrated circuit 2 is controlled by the use of test access enabling keys. A plurality of different test access enabling levels may be supported corresponding to different keys. The test access control may be performed by dedicated hardware or software executing a secure privilege mode.
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Citations
25 Claims
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1. An integrated circuit comprising:
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a test circuit configured to perform test operations upon at least a portion of said integrated circuit; and a test rights controller configured to receive and authenticate a test access request;
whereinif a received test access request passes authentication by said test rights controller, then said test rights controller is configured to permit said test circuit to perform a level of test operations corresponding to said received test access request; and if said received test access request does not pass authentication by said test rights controller, then said test rights controller is operable to prevent said test circuit performing test operations, wherein said test access request includes a test rights enabling key and said test rights controller comprises; an interface circuit configured to read said test rights enabling key from an external data storage device; and a key authenticator configured to authenticate said test rights enabling key read from said external data storage device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An integrated circuit comprising:
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test circuit means for performing test operations upon at least a portion of said integrated circuit; and test rights controller means for receiving and authenticating a test access request;
whereinif a received test access request passes authentication by said test rights controller means, then said test controller means is configured to permit said test circuit to perform a level of test operations corresponding to said received test access request; and if said received test access request does not pass authentication by said test rights controller, then said test rights controller means is configured to prevent said test circuit means performing test operations, wherein said test access request includes a test rights enabling key and said test rights controller means comprises; an interface circuit means for reading said test rights enabling key from an external data storage device; and a key authentication means for authenticating said test rights enabling key read from said external data storage device.
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14. A method controlling test access to an integrated circuit comprising:
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providing a test circuit configured to perform test operations upon at least a portion of said integrated circuit; and receiving and authenticating a test access request with a test right controller;
wherein if a received test access request passes authentication, then said test circuit is permitted to perform a level of test operations corresponding to said received test access request; andif said received test rights access request does not pass authentication, then said test circuit is not permitted to perform test operations, wherein said test access request includes a test rights enabling key and said test rights controller comprises; an interface circuit configured to read said test rights enabling key from an external data storage device; and a key authenticator configured to authenticate said test rights enabling key read from said external data storage device. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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Specification