Abstract: A method of processor operation using an integrated circuit (IC) can include loading encrypted program code into the IC through a configuration port of the IC and decrypting the encrypted program code using configuration circuitry of the IC. Decryption of the encrypted program code can result in decrypted program code which can be provided to a target destination.

Abstract: A method of regulating a supply voltage (Vgg) provided to a load circuit. The method can include generating at least one reference voltage (Vr1, Vr2, Vr3) having a negative voltage-temperature coefficient. The method further can include applying the reference voltage as a bias voltage (Vbias) to a current sink that is electrically coupled in parallel with a path of a leakage current (Ileak) drawn by the load circuit. A related voltage regulator can include a current sink that is electrically coupled in parallel with a path of a leakage current drawn by a load circuit, and a bias control circuit that generates at least one reference voltage having a negative voltage-temperature coefficient and applies the reference voltage as a bias voltage to a current sink.

Abstract: A method of loading configuration data within an integrated circuit that includes multiple dies is disclosed. The method can include receiving configuration data in encrypted form within a first die of the multiple dies of the integrated circuit and decrypting the configuration data within the first die to generate configuration data in unencrypted form. A portion of the configuration data in unencrypted form can be distributed from the first die to each other die of the multiple dies through an interposer to which each die is attached.

Abstract: An embodiment of an integrated circuit (IC) is described. This embodiment of the IC includes an interposer; a first die on an interposer, where the first die generates a global signal propagated through the interposer; and a second die on the surface of the interposer and coupled to the global signal. The first die and the second die each is configured to implement a same operating state concurrently in response to the global signal.

Abstract: A system for uniform power regulation of an integrated circuit is disclosed. In each of a plurality of regions, the system includes a comparison circuit having a first input coupled to receive a reference voltage and a second input coupled to receive a feedback voltage. The comparison circuit provides a gating voltage to a driver circuit that is coupled to a first supply voltage. The driver circuit is configured to provide a regulated voltage responsive to the gating voltage. A feedback adjustment circuit is configured to trim the regulated voltage by a region-specific trim value and output the trimmed regulated voltage as the feedback voltage on the output.

Abstract: In one embodiment of the invention, a method is provided for protecting against attacks on security of a programmable integrated circuit (IC). At least a portion of an encrypted bitstream input to the programmable IC is decrypted with a cryptographic key stored in the programmable IC. A number of failures to decrypt the encrypted bitstream is tracked. The tracked number is stored in a memory of the programmable IC that retains the number across on-off power cycles of the programmable IC. In response to the number of failures exceeding a threshold, data that prevents the decryption key from being used for a subsequent decryption of a bitstream is stored in the programmable IC.

Abstract: An embodiment of an integrated circuit (IC) is described. This embodiment of the IC includes an interposer; a first die on an interposer, where the first die generates a global signal propagated through the interposer; and a second die on the surface of the interposer and coupled to the global signal. The first die and the second die each is configured to implement a same operating state concurrently in response to the global signal.

Abstract: A method of configuring an integrated circuit (IC) can include receiving configuration data within a master die of the IC. The IC can include the master die and a slave die. A master segment and a slave segment of the configuration data can be determined. The slave segment of the configuration data can be distributed to the slave die of the IC.

Abstract: A method of synchronizing transitions between voltage sources that are used to provide a supply voltage. A first control signal (CSclamp) that indicates whether to initiate a first transition from a first voltage source to a second voltage source to provide the supply voltage (Vgg). When the first control signal indicates to initiate a first transition from a first voltage source to a second voltage source to provide the supply voltage, the first voltage source can be deactivated from providing the supply voltage. In addition, the first voltage source can be pre-biased with a voltage pre-bias to facilitate a second transition from the second voltage source to the first voltage source. Further, the second voltage source can be activated to provide the supply voltage.

Abstract: A method and apparatus is provided to enhance the power-up sequence for integrated circuits (ICs) that contain memory cells having single-ended data inputs with no local reset function. During a power-up sequence, the logic levels that are applied to the data, address, and power inputs of the memory cell are restricted to particular magnitudes by a power-on reset (POR) state machine. First, the data input of the memory cell is held to a logic low value while an address signal of the memory cell is allowed to be asserted to a logic high value in conjunction with activating a power supply that provides operational power to the IC. Next, the address input to the memory cell ramps up to full logic high value, while the regulated power supply to the memory cell array is held low. The regulated power supply then ramps up to an operational level to bias the memory cell into a known logic state.

Abstract: An integrated circuit system (120) includes a memory array (122) storing a configuration data set to configure an integrated circuit. The integrated circuit (121) includes a configuration memory (128) and a configuration controller state machine (126). The configuration controller state machine operates so as to read a read-check signature at a read-check address of the memory array (122) and to compare the read-check signature with a standard signature stored in the integrated circuit (121). If the read-check signature passes the comparison, the configuration controller state machine (126) loads the configuration data set from the memory array to the configuration memory (128) of the integrated circuit.

Abstract: A method of validating a bitstream loaded into a circuit having a programmable circuit is disclosed. According to one embodiment, the method comprises steps of loading a configuration bitstream comprising an error detection command at an input of the circuit; decoding the bitstream; providing a signal indicating that an error detection should be performed to a state machine when an error detection command has been decoded; and restarting the loading of the configuration bitstream if the signal has not been received. A device having a programmable circuit is also disclosed.

Abstract: Method and apparatus for providing secure programmable logic devices is described. One aspect of the invention relates to securing a programmable logic device having instruction register logic coupled to control logic via an instruction bus. A non-volatile memory is provided for storing at least one security bit for at least one instruction associated with the programmable logic device. Gating logic is provided in communication with the non-volatile memory and at least a portion of the instruction bus. The gating logic is configured to selectively gate decoded instructions transmitted from the instruction register logic towards the control logic based on state of the at least one security bit.

Abstract: Multiple configurations are provided for a programmable logic device (PLD), such as a field programmable gate array (FPGA), when connected to a serial peripheral interface programmable read only memory (SPI PROM) by using a programmable SPI address register incorporated into a SPI state machine of the PLD. A read command followed by a first address corresponding to first configuration data is sent from the SPI address register of the SPI state machine of the PLD to the SPI PROM. Data starting at the first address in the SPI PROM is then read by the PLD from the SPI PROM along with a second address corresponding to second configuration data. The first configuration data is stored in the PLD memory, and the second address is stored in the SPI address register. These steps may be repeated for subsequent boots of the PLD for additional configurations of the PLD.

Abstract: A programmable device having a multi-boot capability is described. The programmable device may initially load first configuration data for configuring programmable resources of the device. Thereafter, a multi-boot operation may be triggered, causing the device to reconfigure and load second configuration data. Prior to loading the second configuration data, the device may store status information. In some cases, further multi-boot operations may be triggered for loading other configuration data.

Abstract: System and apparatus for data validation is described. An initialization controller includes an initialization state machine. The initialization state machine is configured to cause configuration data to be transferred from memory internal or external to the integrated circuit to other memory internal to the integrated circuit. The configuration data is stored in the integrated circuit, read back from storage in the integrated circuit, and compressed by the integrated circuit after being read back. The configuration data is compressed into a signature, which may be compared with an expected result for the signature.

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.

Abstract: A voltage detector circuit such as a power up and/or brownout detector circuit (100) includes a comparator (102) having at least one of its inputs (104) coupled to a diode-connected transistor (108). The other input can include another diode-connected transistor (110) or a resistor divider (302). Optional compensation capacitors (118 and 120) can be added to the comparator output (116) to provide glitch compensation. Since comparator (102) only needs to output a high or low voltage level, the components that are used to build circuit (100) do not have to have very tight tolerances. Circuit (100) also can operate at very low voltages and consume low amounts of power.

Abstract: Described are programmable logic devices with configuration memory cells that function both as RAM and ROM. A PLD incorporating these memory cells to store configuration data can be mask-programmed with a customer design, rendering the PLD an application-specific integrated circuit (ASIC). The mask programming can be selectively disabled, in which case each configuration memory cell behaves as a static, random-access memory (SRAM) bit. In this mode, a PLD employing these dual-mode memory cells behaves as a reprogrammable PLD, and can therefore be tested using generic test procedures developed for the PLD. The dual-mode memory cells thus eliminate the burdensome task of developing application-specific test procedures for designs ported from a PLD. As an added benefit, in the ROM mode these memory cells are not susceptible to radiation-induced upsets, so for example, PLDs incorporating these memory cells are better suited for aerospace applications than conventional SRAM-based PLDs.

Abstract: Method and apparatus for data transfer validation is described. Configuration data is obtained. A signature for the configuration data is generated. The configuration data and the signature are stored in a first memory. The configuration data is transferred to a second memory for storage. The configuration data transferred is read to generate another signature, where the other signature is for the configuration data transferred. The configuration data read is compressed to provide the other signature. The signature is transferred for comparison with the other signature to validate whether the configuration data transferred was transferred without error. The method and apparatus may be used when transferring configuration data, including, but not limited to, transfer of configuration data from a memory to a programmable logic device.