Security (e.g., Access Or Copy Prevention, Etc.) Patents (Class 326/8)
  • Patent number: 7242217
    Abstract: Techniques for reducing the frequency of an output signal from a hard intellectual property (HIP) block on an integrated circuit are provided. By reducing the frequency of the output signal, circuit blocks in the integrated circuit that operate at a lower frequency than the HIP block are able to capture the output signal. A plurality of serially coupled flip-flops store values of an HIP output signal during each period of the output signal. Logic circuitry then generates a lower frequency HIP output signal in response to the values stored in the flip-flops. Also, a flip-flop can generate a heartbeat signal that is used to determine whether a signal within an HIP block is operating properly.
    Type: Grant
    Filed: December 1, 2004
    Date of Patent: July 10, 2007
    Assignee: Altera Corporation
    Inventors: Darren van Wageningen, Curt Wortman
  • Patent number: 7224178
    Abstract: By adding redundant logic gates into a circuit without changing function of the whole circuit, the present invention can tolerate certain delay variations. The present invention can be applied in the IC industries to improve the yield in semiconductor manufacturing.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: May 29, 2007
    Assignee: National Tsing Hua University
    Inventor: Shih-Chieh Chang
  • Patent number: 7205794
    Abstract: A secure microprocessor is designed using quad-coded logic which is similar to dual-rail encoded asynchronous logic except that the ‘11’ state propagates an alarm. The alarm signal obliterates secure data in its path. Quad-coded logic provides resilience to power glitches and single-transistor or single-wire failures. The already low data dependency of the power consumption makes power analysis attacks difficult, and they are made even more difficult by inserting random delays in data and control paths, and by a set-random-carry instruction which enables software to make a non-deterministic choice between equivalent instruction sequences. These features are particularly easy to implement well in quad-coded logic.
    Type: Grant
    Filed: January 26, 2001
    Date of Patent: April 17, 2007
    Inventors: Ross John Anderson, Simon William Moore
  • Patent number: 7205785
    Abstract: An apparatus is described comprising: a set of logic blocks configured to perform designated data processing functions; a set of redundant logic blocks also configured to perform the designated data processing functions; and a logic block selector module to replace one or more of the set of logic blocks with one or more of the set of redundant logic blocks according to specified logic block replacement conditions.
    Type: Grant
    Filed: January 20, 2005
    Date of Patent: April 17, 2007
    Assignee: Cavium Networks, Inc.
    Inventor: David A. Carlson
  • Patent number: 7200235
    Abstract: Described are circuits that detect and correct for decryption key errors. In one example, a programmable logic device includes a decryption key memory with a number of decryption-key fields and, for each key field, an associated error-correction-code (ECC) field. The PLD additionally includes error-correction circuitry that receives each key and associated ECC and performs an error correction before conveying the resulting error-corrected key to a decryptor.
    Type: Grant
    Filed: May 17, 2002
    Date of Patent: April 3, 2007
    Assignee: Xilinx, Inc.
    Inventor: Stephen M. Trimberger
  • Patent number: 7200759
    Abstract: A method is disclosed of making information contents of memory-cells of a volatile semiconductor memory irretrievable. In a first step a digital pattern is generated and in a second step the information contents are overwritten with the digital pattern at least two times. The digital pattern is predefined, comprising both zeros and ones and overwrites the information contents alternately with its complementary pattern.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: April 3, 2007
    Assignee: Safenet B.V.
    Inventor: Robert Vincent Michel Oerlemans
  • Patent number: 7199603
    Abstract: An integrated circuit having a device with an adjustable parameter utilizes a two signal control protocol to select the device, perform an up/down or increment/decrement of the parameter value with or without saving the parameter value in a non-volatile memory of the integrated circuit.
    Type: Grant
    Filed: September 21, 2004
    Date of Patent: April 3, 2007
    Assignee: Microchip Technology Incorporated
    Inventor: James Simons
  • Patent number: 7183799
    Abstract: A programmable logic device may comprise a metric circuit operable to repeatedly perform a function and emit a first signal dependent upon its advancement into the function. A comparator may compare the first signal from the metric circuit to a predetermined reference signal. A controller may then selectively disable a portion of the programmable logic device dependent upon the results of the comparison. In a particular case, the weakened circuit may be a counter that repeatedly advances its count with a rate dependent upon an aging characteristic of a vulnerable element.
    Type: Grant
    Filed: February 25, 2005
    Date of Patent: February 27, 2007
    Assignee: Xilinx, Inc.
    Inventors: Adam P. Donlin, Stephen M. Trimberger
  • Patent number: 7180776
    Abstract: On-the-fly reconfiguration of a secured CPLD. In one embodiment, a CPLD includes a novel security circuit that provides two different security control signals: an EEPROM/SRAM security signal and an EEPROM security override signal. The EEPROM/SRAM security signal prevents reading from both the EEPROM and the SRAM, and also prevents writing to the EEPROM. The EEPROM security override signal enables reading and writing for the EEPROM even when otherwise disabled by the EEPROM/SRAM security signal, but is active only when a specific set of conditions are met. These conditions can include, for example, the application of a sufficiently long erase pulse to the EEPROM array. Thus, the security on the EEPROM array is overridden only after the configuration data set stored in the EEPROM array has been erased. Reading from the SRAM is not enabled by the EEPROM security override signal. Therefore, the configuration data set is not compromised.
    Type: Grant
    Filed: February 1, 2005
    Date of Patent: February 20, 2007
    Assignee: Xilinx, Inc.
    Inventors: Wayne Edward Wennekamp, Eric E. Edwards, Roy D. Darling
  • Patent number: 7162644
    Abstract: Described are various methods and systems for encrypting/decrypting configuration data for programmable logic devices. In configuration data defining a number of separately encrypted subdesigns, or “cores,” each subdesign includes a shared password or a unique authentication code to ensure the designs belong together. Other embodiments prohibit the overwriting of configuration memory to prevent the inclusion of unauthorized designs. Still other embodiments protect key secrecy while enabling users to read, write, and verify the keys.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: January 9, 2007
    Assignee: Xilinx, Inc.
    Inventor: Stephen M. Trimberger
  • Patent number: 7127620
    Abstract: A coding device for implementing a cryptographic encryption and/or access authorization includes a data processing unit, a decoupling unit, a power supply interface, a main clock supply unit, and a power profile generator generating a power profile and superimposing it on a power profile of the data processing unit to prevent an attack by correlation analysis of the power profile.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: October 24, 2006
    Assignee: Infineon Technologies AG
    Inventor: Gregor Boeckeler
  • Patent number: 7106091
    Abstract: A circuit configuration for detecting an unwanted attack on an integrated circuit has a signal line to which a clock signal is applied and at least one line pair which is respectively used to code a bit. The signal line and the at least one line pair are connected between a first and a second circuit block in the integrated circuit. The signal line and the at least one line pair are connected to a detector circuit which changes the operating sequence in the integrated circuit on the basis of the signals on the signal line and on the at least one line pair. The detector circuit can be used to the same extent to test for production faults.
    Type: Grant
    Filed: March 11, 2003
    Date of Patent: September 12, 2006
    Assignee: Infineon Technologies AG
    Inventor: Berndt Gammel
  • Patent number: 7091740
    Abstract: An integrated circuit having a device with an adjustable parameter utilizes a two signal control protocol to select the device, change the parameter value with or without saving the parameter value in a non-volatile memory, and to write protect the parameter value in the non-volatile memory.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: August 15, 2006
    Assignee: Microchip Technology Incorporated
    Inventor: James Simons
  • Patent number: 7085857
    Abstract: Methods, systems, apparatuses, and arrangements enable an identifier module of a storage system to be rendered unusable upon removal from the storage system. In an exemplary identifier module implementation, the identifier module includes an identifier data space that is capable of receiving an identifier and a breakable apparatus that is adapted to break and render the identifier module unusable upon removal of the identifier module from a storage system. The identifier module may be adapted for removable attachment to the storage system. In an exemplary storage system implementation, the storage system includes one or more memory units that are capable of storing information and at least one interface that is adapted to receive an identifier module. The at least one interface includes a disrupter apparatus that is adapted to break and render unusable an identifier module upon removal of such an identifier module from the at least one interface.
    Type: Grant
    Filed: November 13, 2002
    Date of Patent: August 1, 2006
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Robert A. Rust, James P. Slupe, Patrick F. Donnelly, III, Richard G. Sevier
  • Patent number: 7071725
    Abstract: A data processing apparatus comprises a plurality of input signal lines, a plurality of output signal lines and an electronic circuit. The electronic circuit inputs first data from the plurality of input signal lines and outputs second data to the plurality of output signal lines. The first data is one bit data represented by a combination of bits of the plurality of input signal lines. The second data is one bit data represented by a combination of bits of the plurality of output signal lines.
    Type: Grant
    Filed: May 20, 2004
    Date of Patent: July 4, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Koichi Fujisaki
  • Patent number: 7071726
    Abstract: Improved communication, and an improved communication interface, between the core PLD fabric of a PLD and embedded IP building blocks resident therein is provided. A circuit according to the invention may include at least two different signal paths between the PLD core fabric and embedded IP building blocks. Either one, or both, of these two paths may be used for configuration and/or implementation of the embedded IP building blocks.
    Type: Grant
    Filed: December 1, 2004
    Date of Patent: July 4, 2006
    Assignee: Altera Corporation
    Inventors: Vinson Chan, Chong Lee, Rakesh Patel, Ramanand Venkata, Binh Ton
  • Patent number: 7017048
    Abstract: Differential power analysis on an integrated circuit is made more difficult by providing a circuit configuration for generating current pulses in the supply current of the integrated circuit. These additional pulses that are generated in the supply current are synchronous with the edges of the internal clock signal of the integrated circuit. In this case, the pulse shape and also the amplitude and the time profile are similar to the pulses in the supply current which are generated by other circuit sections, for example by processors or by some other digital logic, and in digital circuits, typically correspond to a charging curve of a capacitor via a resistor. The circuit generates these additional pulses by using a delay element.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: March 21, 2006
    Assignee: Infineon Technologies AG
    Inventors: Otto Schneider, Dirk Uffmann
  • Patent number: 7009419
    Abstract: A method and circuit for preventing external access to secure data of an integrated circuit while supporting DFT is disclosed. In accordance with the method the integrated circuit is automatically placed into the test mode at integrated circuit power-up from a power-down state. At power up, secure data is other than present within a secure data-path of the integrated circuit. Access is provided to the secure data path via a second data path coupled with the first secure data-path. Via the access path, data other than secure data is provided to the integrated circuit, the data for performing test functions of the integrated circuit operating in the test mode. Once data other than secure data is provided to first secure data path, the test mode is terminated and access via other than the secure ports is disabled. The test mode is only re-entered by powering down the integrated circuit and re-initialising it.
    Type: Grant
    Filed: October 16, 2003
    Date of Patent: March 7, 2006
    Assignee: Mosaid Technologies, Inc.
    Inventor: James Goodman
  • Patent number: 6981153
    Abstract: It is sometimes desirable to protect a design used in a PLD from being copied. If the design is stored in a different device from the PLD and read into the PLD through a bitstream, the design may be encrypted as it is read into the PLD and decrypted within the PLD before being loaded into configuration memory cells for configuring the PLD. According to the invention, in such a device, a method is provided to prevent the design from being read back from the PLD in its decrypted state if it had been encrypted when loaded into the PLD.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: December 27, 2005
    Assignee: Xilinx, Inc.
    Inventors: Raymond C. Pang, Walter N. Sze, John M. Thendean, Stephen M. Trimberger, Jennifer Wong
  • Patent number: 6933742
    Abstract: A circuit for monitoring an entry into a test mode of a chip circuit has a fusible link which can be fired via a firing transistor. A flipflop, which permits access to the test mode, is set by a resulting voltage drop, with the aid of an edge detector. The number of times the test mode has been accessed can be detected from the number of fired fusible links.
    Type: Grant
    Filed: July 18, 2002
    Date of Patent: August 23, 2005
    Assignee: Infineon Technologies AG
    Inventor: Stefan Wallstab
  • Patent number: 6924663
    Abstract: A programmable logic device with ferroelectric configuration memories storing multiple configuration data sets. The device has programmable logic blocks, interconnections, and I/O blocks to provide desired logic functions. Those building blocks can be dynamically reconfigured by changing the selection of configuration data stored in the device's integral configuration memories. The configuration memories are divided into groups, so that they can be loaded concurrently with multiple configuration data streams. To protect the content of configuration memories from unauthorized access, the device employs an authentication mechanism that uses security IDs stored in the configuration memories. The device has a memory controller to provide an appropriate power supply sequence for ferroelectric memory cells to ensure the reliable data retention when the device is powered up or shut down.
    Type: Grant
    Filed: December 24, 2002
    Date of Patent: August 2, 2005
    Assignee: Fujitsu Limited
    Inventors: Shoichi Masui, Michiya Oura, Tsuzumi Ninomiya, Wataru Yokozeki, Kenji Mukaida
  • Patent number: 6894527
    Abstract: A security circuit for a reprogrammable logic IC includes an evolved circuit that ties the performance of the security circuit to the physical properties of that particular reprogrammable logic IC. The security circuit can be a decryption and/or encryption circuit that decrypts and/or encrypts, respectively, a configuration bitstream for the IC. Because of the link between the performance of the security circuit and the physical properties of the IC, the security circuit cannot be used in other ICs. For example, an encrypted bitstream that can be decrypted by the security circuit in a first IC will typically not be decrypted by the same security circuit in a second IC, since the physical properties of the two ICs will typically be different. The evolved circuit can comprise a portion of the security circuit, such as a security key generator, or it can comprise the full security circuit.
    Type: Grant
    Filed: May 12, 2003
    Date of Patent: May 17, 2005
    Assignee: Xilinx, Inc.
    Inventors: Adam P. Donlin, Stephen M. Trimberger
  • Patent number: 6874069
    Abstract: A single integrated circuit microcontroller 10 includes an embedded erasable/programmable non-volatile memory 12 having a read protection capability. Microcontroller 10 can operate within a special mode in which external circuits may access memory 12 by use of input/output pins 18. When microcontroller 10 activates this special mode, a read protection flag 13 within memory 12 is checked. The read protection flag 13 may be set during production of the microcontroller 10 after instructional data or firmware has been installed onto memory 12. If the read protection flag 13 has been set, only certain portions of the memory 12 may be read, depending upon the value of the read protection flag 13.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: March 29, 2005
    Assignee: Silicon Storage Technology, Inc.
    Inventors: Fong-Long Lin, Xiangyang Teng
  • Patent number: 6873177
    Abstract: On-the-fly reconfiguration of a secured CPLD. In one embodiment, a CPLD includes a novel security circuit that provides two different security control signals: an EEPROM/SRAM security signal and an EEPROM security override signal. The EEPROM/SRAM security signal prevents reading from both the EEPROM and the SRAM, and also prevents writing to the EEPROM. The EEPROM security override signal enables reading and writing for the EEPROM even when otherwise disabled by the EEPROM/SRAM security signal, but is active only when a specific set of conditions are met. These conditions can include, for example, the application of a sufficiently long erase pulse to the EEPROM array. Thus, the security on the EEPROM array is overridden only after the configuration data set stored in the EEPROM array has been erased. Reading from the SRAM is not enabled by the EEPROM security override signal. Therefore, the configuration data set is not compromised.
    Type: Grant
    Filed: August 12, 2003
    Date of Patent: March 29, 2005
    Assignee: Xilinx, Inc.
    Inventors: Wayne Edward Wennekamp, Eric E. Edwards, Roy D. Darling
  • Patent number: 6842034
    Abstract: Improved communication, and an improved communication interface, between the core PLD fabric of a PLD and embedded IP building blocks resident therein is provided. A circuit according to the invention may include at least two different signal paths between the PLD core fabric and embedded IP building blocks. Either one, or both, of these two paths may be used for configuration and/or implementation of the embedded IP building blocks.
    Type: Grant
    Filed: July 1, 2003
    Date of Patent: January 11, 2005
    Assignee: Altera Corporation
    Inventors: Vinson Chan, Chong Lee, Rakesh Patel, Ramanand Venkata, Binh Ton
  • Patent number: 6842386
    Abstract: A semiconductor integrated circuit includes a main memory unit, a redundancy memory unit and a redundancy information file unit, wherein at least a part of data that would otherwise be stored in the main memory is stored in the redundancy memory unit according to redundancy information stored in the redundancy information file unit, thereby secrecy of the data stored in this manner is enhanced.
    Type: Grant
    Filed: March 21, 2002
    Date of Patent: January 11, 2005
    Assignee: Fujitsu Limited
    Inventor: Hideaki Suzuki
  • Patent number: 6819133
    Abstract: A system for protecting configuration data of a programmable execution unit (PEU) comprises a programmable array and programming logic. The programming logic is configured to receive configuration data and to program the programmable array, based on the configuration data, such that the programmable array comprises functional logic and activation logic. The activation logic is configured to enable the functional logic upon detection of an activation key.
    Type: Grant
    Filed: July 3, 2003
    Date of Patent: November 16, 2004
    Assignee: ADTRAN, Inc.
    Inventors: Matthew A. Kliesner, Timothy G. Mester
  • Patent number: 6813695
    Abstract: A cache memory serves for accelerating accesses to an external memory of a microprocessor. Instead of an actually occurring hit event, a cache miss is signaled to the microprocessor. The reversal is randomly controlled. This disguises the current profile of cache hit and miss events, which enhances the security against statistical attack techniques based on the evaluation of the current profile.
    Type: Grant
    Filed: July 11, 2002
    Date of Patent: November 2, 2004
    Assignee: Infineon Technologies AG
    Inventors: Berndt Gammel, Michael Smola
  • Patent number: 6788097
    Abstract: A programmable logic device includes a function block to generate a power control signal that is distributed on a rail to selectively power down various components on the device. The rail is coupled to an observation pin to allow for external observation of the power control signal. The power control signal is also provided as a feed forward signal to an input signal blocking circuit, which selectively enables or disables the device input pins in response to the feed forward signal. The feed forward signal is not accessible from the observation pin, and therefore cannot be externally altered from the observation pin.
    Type: Grant
    Filed: April 30, 2003
    Date of Patent: September 7, 2004
    Assignee: Xilinx, Inc.
    Inventors: Jesse H. Jenkins, IV, Shankar Lakkapragada
  • Patent number: 6768337
    Abstract: A plurality of circuit cells, a plurality of matrix switch sections and a plurality of switch sections for connecting between the plurality of circuit cells, all of which form a part of a circuit cell array, and a plurality of input/output cell sections arranged around the circuit cell array all change their circuit configurations in accordance with a configuration data to be supplied. In some of these circuit blocks, at least a part of the circuit thereof is fixed at a predetermined circuit configuration, and a conversion of the configuration data based on proprietary information regarding the fixed circuit is performed at a supplier of the configuration data. Thus, a differential configuration data for portions of the circuit other than the fixed circuit portion is generated and supplied to the integrated circuit.
    Type: Grant
    Filed: August 19, 2002
    Date of Patent: July 27, 2004
    Assignee: Sony Corporation
    Inventors: Ryuji Kohno, Kenichiro Akai, Yukitoshi Sanada, Robert Morelos-Zaragoza, Lachlan Michael
  • Patent number: 6762617
    Abstract: A semiconductor device has a normal operation mode and a test mode. A decision circuit determines whether the device has entered the test mode. A control circuit changes information related to the normal operation mode when a test mode has been entered. If the test mode is accidentally entered, then because the information related to normal operation has been changed, a user can readily determine that the device has entered the test mode.
    Type: Grant
    Filed: December 18, 2002
    Date of Patent: July 13, 2004
    Assignee: Fujitsu Limited
    Inventors: Akihiro Iwase, Yoshiharu Kato
  • Patent number: 6748368
    Abstract: A programmable logic device includes a non-volatile permission memory block to enable a customer to utilize a proprietary core. In one embodiment, the core supplier designs its core to check for a specified permission bit or bit pattern in the permission memory block before the core will operate. If the permission bit or bit pattern is set properly, the core functions correctly when implemented in the PLD. If not, the core will not function. To prevent the customer from modifying the core such that it no longer depends upon the permission bits to function, the configuration bitstream used to program the PLD can be encrypted before and during transmission to the PLD. This encryption ensures security of the customer's logic design as well as the supplier's core design. In this manner, the customer remains dependent upon properly set permission memory bits, i.e. proper authorization, to obtain core functionality.
    Type: Grant
    Filed: January 5, 2000
    Date of Patent: June 8, 2004
    Assignee: Xilinx, Inc.
    Inventors: Stephen M. Trimberger, William S. Carter
  • Patent number: 6664803
    Abstract: A method and circuit for preventing external access to secure data of an integrated circuit while supporting DFT is disclosed. In accordance with the method the integrated circuit is automatically placed into the test mode at integrated circuit power-up from a power-down state. At power up, secure data is other than present within a secure data-path of the integrated circuit. Access is provided to the secure data path via a second data path coupled with the first secure data-path. Via the access path, data other than secure data is provided to the integrated circuit, the data for performing test functions of the integrated circuit operating in the test mode. Once data other than secure data is provided to first secure data path, the test mode is terminated and access via other than the secure ports is disabled. The test mode is only re-entered by powering down the integrated circuit and re-initialising it.
    Type: Grant
    Filed: June 20, 2002
    Date of Patent: December 16, 2003
    Assignee: MOSAID Technologies, Inc.
    Inventor: James Goodman
  • Publication number: 20030218475
    Abstract: A circuit configuration for detecting an unwanted attack on an integrated circuit has a signal line to which a clock signal is applied and at least one line pair which is respectively used to code a bit. The signal line and the at least one line pair are connected between a first and a second circuit block in the integrated circuit. The signal line and the at least one line pair are connected to a detector circuit which changes the operating sequence in the integrated circuit on the basis of the signals on the signal line and on the at least one line pair. The detector circuit can be used to the same extent to test for production faults.
    Type: Application
    Filed: March 11, 2003
    Publication date: November 27, 2003
    Inventor: Berndt Gammel
  • Patent number: 6535016
    Abstract: A method for preventing illicit copying of an application specific integrated circuit (ASIC). The ASIC is defined by a net list which includes a timer circuit for disabling the ASIC. The timer circuit includes a plurality of stages which are distributed in different cores of the ASIC to inhibit detection and removal of the circuit. The timer times out after a period which is set to permit evaluation of the ASIC design. Following the time out period, further use of the ASIC design is inhibited.
    Type: Grant
    Filed: May 11, 2001
    Date of Patent: March 18, 2003
    Assignee: International Business Machines Corporation
    Inventors: Charles N. Choukalos, Alvar A. Dean, Scott A. Tetreault, Sebastian T. Ventrone
  • Patent number: 6525557
    Abstract: A core for a register-based programmable logic device includes a register configured to provide a hidden identifier in response to a secret unlock operation. The identifier is inaccessible during normal operation of the core implementation. The unlock operation is selected to be an action or set of actions that would typically not be performed during normal use of the core implementation. The logic associated with providing the hidden identifier in response to the unlock operation is configured to not interfere with normal operation of the core implementation. Therefore, the presence of this source identification capability is transparent to regular users (and unauthorized copyists) of the core implementation. The availability of the secondary identifier can be limited in duration to minimize the chances of accidental, or even intentional, discovery.
    Type: Grant
    Filed: November 2, 2001
    Date of Patent: February 25, 2003
    Assignee: Xilinx, Inc.
    Inventors: James L. McManus, Eric J. Crabill, James L. Burnham
  • Patent number: 6489810
    Abstract: An electronic circuit with digital output including an auto-stable assembly of latches (1), a control assembly (2), a blowable assembly (3), a logic gate (4) including a first input connected to a common point (14) between the auto-stable assembly (1) and the blowable assembly (3), and a second input connected to the control input (20) of the electronic circuit. A breaker (5) is controlled by the output of the logic gate (4) and arranged between the auto-stable assembly (1) and ground, and an associated process.
    Type: Grant
    Filed: June 26, 2001
    Date of Patent: December 3, 2002
    Assignee: STMicroelectronics S.A.
    Inventor: Richard Ferrant
  • Publication number: 20020175698
    Abstract: A method and circuit for preventing external access to secure data of an integrated circuit while supporting DFT is disclosed. In accordance with the method the integrated circuit is automatically placed into the test mode at integrated circuit power-up from a power-down state. At power up, secure data is other than present within a secure data-path of the integrated circuit. Access is provided to the secure data path via a second data path coupled with the first secure data-path. Via the access path, data other than secure data is provided to the integrated circuit, the data for performing test functions of the integrated circuit operating in the test mode. Once data other than secure data is provided to first secure data path, the test mode is terminated and access via other than the secure ports is disabled. The test mode is only re-entered by powering down the integrated circuit and re-initialising it.
    Type: Application
    Filed: June 20, 2002
    Publication date: November 28, 2002
    Applicant: MOSAID Technologies, Inc.
    Inventor: James Goodman
  • Patent number: 6466048
    Abstract: A method and circuit for preventing external access to secure data of an integrated circuit while supporting DFT is disclosed. In accordance with the method the integrated circuit is automatically placed into the test mode at integrated circuit power-up from a power-down state. At power up, secure data is other than present within a secure data-path of the integrated circuit. Access is provided to the secure data path via a second data path coupled with the first secure data-path. Via the access path, data other than secure data is provided to the integrated circuit, the data for performing test functions of the integrated circuit operating in the test mode. Once data other than secure data is provided to first secure data path, the test mode is terminated and access via other than the secure ports is disabled. The test mode is only re-entered by powering down the integrated circuit and re-initializing it.
    Type: Grant
    Filed: May 23, 2001
    Date of Patent: October 15, 2002
    Assignee: Mosaid Technologies, Inc.
    Inventor: James Goodman
  • Patent number: 6459298
    Abstract: A structure of controlled pipeline logic is disclosed. A random noise generator is added to the controlled pipeline logic. Moreover, each combinational logic element of the controlled pipeline logic is appended with an active bit. When no input flows into the controlled pipeline logic, the random noise generator will generate random noises, and the active bit will enforce the combinational logic element to accept the random noise as an input so that the controlled pipeline logic is always sustained in the active condition. The controlled pipeline logic is not exposing the internal functions thereof and avoiding improper monitoring and observation.
    Type: Grant
    Filed: August 7, 2001
    Date of Patent: October 1, 2002
    Assignee: Geneticware Co., Ltd.
    Inventors: Chien-Tzu Hou, Hsiu-Ying Hsu
  • Patent number: 6381732
    Abstract: A field programmable gate array (FPGA) is provided that can selectively accept or reject selected software (macros). Specifically, configuration data for the FPGA is passed through a configuration port to a decoder. The decoder processes the configuration data to detect locked macros. If a locked macro is detected, the decoder attempts to unlock the locked macro using one or more keys stored in a key table of the FGPA. If an appropriate key is in the key table, the decoder unlocks the locked macro to configure the FPGA. The keys can be pre-programmed into the FGPA by the macro vendor. If configuration data containing a locked macro is used with an FPGA without the appropriate key, configuration of the FPGA fails.
    Type: Grant
    Filed: August 7, 2001
    Date of Patent: April 30, 2002
    Assignee: Xilinx, Inc.
    Inventors: James L. Burnham, Gary R. Lawman, Joseph D. Linoff
  • Patent number: 6331784
    Abstract: A programmable logic chip and configuration memory chip are mounted within a multi-chip module to form a single package. The configuration memory has a security bit which in a first state allows programming and read-back of configuration data in the memory chip via external pins of the package, and in a second state allows only erase command to be communicated to the memory chip via the external pins. The internal data transfer connection between the memory chip and programmable logic chip is enabled when the security bit is in the second state and the memory chip is in a read-back mode, allowing configuration data to be loaded into the logic chip upon power up.
    Type: Grant
    Filed: July 28, 2000
    Date of Patent: December 18, 2001
    Assignee: Atmel Corporation
    Inventors: Martin T. Mason, Nancy D. Kunnari, Harry H. Kuo
  • Publication number: 20010045842
    Abstract: A method for preventing illicit copying of an application specific integrated circuit (ASIC). The ASIC is defined by a net list which includes a timer circuit for disabling the ASIC. The timer circuit includes a plurality of stages which are distributed in different cores of the ASIC to inhibit detection and removal of the circuit. The timer times out after a period which is set to permit evaluation of the ASIC design. Following the time out period, further use of the ASIC design is inhibited.
    Type: Application
    Filed: May 11, 2001
    Publication date: November 29, 2001
    Applicant: IBM Corporation
    Inventors: Charles N. Choukalos, Alvar A. Dean, Scott A. Tetreault, Sebastian T. Ventrone
  • Patent number: 6316959
    Abstract: A semiconductor circuit for compressing or encoding output data of a scan path circuit, able to realize a circuit test and fault analysis by the scan path circuit, and capable of preventing the configuration of a combinational circuit from being guessed from the input and output. Predetermined mode key data is input by being mixed in input data to a scan path circuit during a scan mode operation so as to be fetched by a mode key circuit embedded in the scan path circuit. The mode key data is fetched by the mode holding circuit from the mode key circuit and a mode signal BE is generated in accordance with the mode key data during a system mode operation. When the mode key data has a predetermined pattern, the mode key signal becomes a predetermined set value, and an output signal of the scan path circuit is output as it is in accordance therewith. Otherwise, since the output signal of the scan path circuit is encoded and output, the output of the scan path circuit can be concealed in accordance with need.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: November 13, 2001
    Assignee: Sony Corporation
    Inventor: Takeshi Onodera
  • Patent number: 6292012
    Abstract: A device installed in a computer system for protecting the program or data inside a programmable non-volatile memory. The device includes a first and a second combinatorial logic circuit, a delay circuit, a low-enable latching device with reset capability, an AND gate and a memory cell array. As soon as all the necessary system startup operations dictated by the BIOS program inside the memory cell array are executed and a specified memory read/write program that matches the preset internal parameters of a logic circuit is activated so that output from the AND gate is a logic ‘false’, the memory cell array is permanently locked in a non-programmable state, unless the power is turned off and then restarted again. There is no way for any software program to change the programming state of the memory cell array back to a re-programming state again. Hence, the device is an effective means of protecting the programs inside the memory from illegal tampering.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: September 18, 2001
    Assignee: Winbond Electronics Corp.
    Inventors: Tsuei-Chi Yeh, Chung Hsun Ma
  • Patent number: 6246254
    Abstract: A method for preventing illicit copying of an application specific integrated circuit (ASIC). The ASIC is defined by a net list which includes a timer circuit for disabling the ASIC. The timer circuit includes a plurality of stages which are distributed in different cores of the ASIC to inhibit detection and removal of the circuit. The timer times out after a period which is set to permit evaluation of the ASIC design. Following the time out period, further use of the ASIC design is inhibited.
    Type: Grant
    Filed: December 6, 1999
    Date of Patent: June 12, 2001
    Assignee: International Business Machines Corporation
    Inventors: Charles N. Choukalos, Alvar A. Dean, Scott A. Tetreault, Sebastian T. Ventrone
  • Patent number: 6215875
    Abstract: A cipher processing apparatus which readily updates a cipher processing circuit for encrypting information communicated through a communication function. A service station side and a user side are connected. A receiving function receives a command for requesting a change of a cipher processing program and the cipher processing program which are transmitted from the service station side to the user side through the communication function. Circuit updating function updates a cipher processing circuit provided on the user side with the cipher processing program. With these functions, the cipher processing circuit provided on the user side can be readily rewritten in accordance with the cipher processing program transmitted from the service station side.
    Type: Grant
    Filed: January 12, 1998
    Date of Patent: April 10, 2001
    Assignee: Sony Corporation
    Inventor: Shigetoshi Nohda
  • Patent number: 6161184
    Abstract: A data processing apparatus comprises function for receiving a power supply from outside of the apparatus, and erasing a program stored in a volatile memory when the power supply is stopped, function for receiving the program from an external apparatus and storing the program in a volatile memory having no backup battery, and function for processing data in accordance with the stored program.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: December 12, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Takashi Niimura
  • Patent number: 6144314
    Abstract: A wireless selective-call receiver makes use of detection or absence of any to-and-fro movement of the receiver indicating that the receiver has been left somewhere thereby improving the security function of the receiver. When a motion detector detects no continuous shaky movement of the receiver, the message received by the receiver is stored in memory. A controller comprises a first control section which operates in a no movement condition, a second control section which operates in a moving condition, and a switching means for switching from the first control section to the second control section and vice versa. In the absence of the to-and-fro movement of the receiver (for example, the receiver is put away from the owner's body to be left on the desk), any access through a button inputting console and external interface except inputting a password is rejected. The message received is stored in memory, and not given on display, thereby preventing pieces of private information from leaking.
    Type: Grant
    Filed: December 11, 1997
    Date of Patent: November 7, 2000
    Assignee: NEC Corporation
    Inventor: Tadashi Yasue
  • Patent number: 6137318
    Abstract: A constantly conductive MOS transistor is placed in a logic circuit including a plurality of switching MOS transistors. The switching MOS transistors and the constantly conductive MOS transistor are connected in series and each receive a control signal at their respective gates. The constantly conductive transistor is in a conductive state regardless of the state of its control signal. Thus, it is difficult for a third party to learn the true logic structure of the logic circuit by visual inspection, as the third party will tend to recognize the constantly conductive transistor as a true transistor contributing to the logic circuit, and not as a constantly conductive "dummy" transistor.
    Type: Grant
    Filed: October 7, 1998
    Date of Patent: October 24, 2000
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Kodama Takaaki