A system and method to manage a single event latched (SEL) condition, the method including operations to monitor, for a predetermined condition associated with single event latched (SEL) states, a reset signal output from a watchdog device to a microprocessor, wherein the reset signal is responsive to a malfunction condition associated with the microprocessor. The method further includes operations to control provision of power to the microprocessor in response to detection of the predetermined condition.

Push-pull integrated circuit output drivers may interfere with communication by other entities on a bus when an integrated circuit is powered down. When there is no power and/or when the bonding pad is externally driven above the internal supply voltage, the substrate/body/well of the p-channel field effect transistor (PFET) of the output driver is biased to prevent its drain diode from becoming forward biased thereby preventing interference with communication on the bus. Also, when there is no power, driver is powered down or pull up is disabled, the gate of the driver PFET is driven to a voltage that ensures the driver PFET remains off when the bonding pad is externally driven above the internal supply voltage.

Push-pull integrated circuit output drivers may interfere with communication by other entities on a bus when an integrated circuit is powered down. When there is no power and/or when the bonding pad is externally driven above the internal supply voltage, the substrate/body/well of the p-channel field effect transistor (PFET) of the output driver is biased to prevent its drain diode from becoming forward biased thereby preventing interference with communication on the bus. Also, when there is no power, driver is powered down or pull up is disabled, the gate of the driver PFET is driven to a voltage that ensures the driver PFET remains off when the bonding pad is externally driven above the internal supply voltage.

A fail-safe circuit enables a switch to turn on/off according to a signal from an external device if a microcomputer that controls the turning on/off of the switch falls into an abnormal state and is reset, and if the power supply for a circuit that backs up the control of the switch is lost. The fail-safe circuit includes a microcomputer that controls the turning on/off of a switch based on an instruction signal from an input terminal, a watchdog circuit that generates a reset signal based on a watchdog pulse from the microcomputer, and a transistor for masking a watchdog pulse for resetting a flip-flop circuit that is set by the reset signal. If a voltage supplied by a power supply circuit is lost, a transistor turns off, and therefore the switch turns on/off according to an instruction signal supplied to an output terminal via a resistor and a diode.

A fail-safe circuit enables a switch to turn on/off according to a signal from an external device if a microcomputer that controls the turning on/off of the switch falls into an abnormal state and is reset, and if the power supply for a circuit that backs up the control of the switch is lost. The fail-safe circuit includes a microcomputer that controls the turning on/off of a switch based on an instruction signal from an input terminal, a watchdog circuit that generates a reset signal based on a watchdog pulse from the microcomputer, and a transistor for masking a watchdog pulse for resetting a flip-flop circuit that is set by the reset signal. If a voltage supplied by a power supply circuit is lost, a transistor turns off, and therefore the switch turns on/off according to an instruction signal supplied to an output terminal via a resistor and a diode.

A monitor circuit (301) for monitoring changes in an input digital value of a register circuit comprises a data input (302) configured to receive a copy of the input digital value of said register circuit, and one or more triggering signal inputs (303) configured to receive one or more triggering signals. One or more triggering edges thereof define an allowable time limit before which a digital value must appear at a data input of said register circuit to become properly stored in said register circuit. The monitor circuit comprises a data event (DE) output (305), so that said monitor circuit is configured to produce a DE signal at said DE output (305) in response to a digital value at said data input (302) changing within a time window defined by said one or more triggering signals.

A programmable IC is disclosed that includes a programmable logic sub-system, a processing sub-system, and a safety sub-system. The programmable logic sub-system is configured to operate a hardware portion of the user design. The processing sub-system configured to execute a software portion of the user design. The safety sub-system is configured to perform a set of operations to detect errors in the programmable IC. The first set of operations writes to at least one of a set of registers using a write macro function. In response to writing to the register with the write macro function, a list of registers stored in the memory is updated to include the register. Registers included in the list of registers are tested to determine whether or not an upset has occurred.

A programmable IC is disclosed that includes a programmable logic sub-system, a processing sub-system, and a safety sub-system. The programmable logic sub-system is configured to operate a hardware portion of the user design. The processing sub-system configured to execute a software portion of the user design. The safety sub-system is configured to perform a set of operations to detect errors in the programmable IC. The first set of operations writes to at least one of a set of registers using a write macro function. In response to writing to the register with the write macro function, a list of registers stored in the memory is updated to include the register. Registers included in the list of registers are tested to determine whether or not an upset has occurred.

Described herein is a method implemented by circuitry for providing fault tolerance in a combinational circuit. The circuitry identifies sensitive gates of the circuit that require protection from at least one of a first type of fault and a second type of fault. Further, circuitry computes for each first type of transistor included in the sensitive gate, a first failure probability, and for each second type of transistor included in the sensitive gate, a second failure probability. The circuitry calculates a first parameter corresponding to a number of the first type of transistors for which the computed first failure probabilities exceed a first predetermined threshold and a second parameter corresponding to a number of second type of transistors for which the computed second failure probabilities exceed a second predetermined threshold to determine a protection type based on an area overhead constraint.

A trim/test interface in a packaged integrated circuit device prevents high through-current between pins of the IC device and trim/test interface digital logic within the IC device using a floating-pin-tolerant always-on CMOS input buffer. The always-on buffer uses a coupling capacitor at its input to block signals at DC and a weak-latch feedback path to ensure that intermediate or floating inputs are provided through the buffer only at one of two digital levels (e.g., those provided by a ground pin GND and by a high supply voltage pin VDD). The described interfaces and methods provide for false-entry-free test mode activation for IC devices with a low pin count, where there are a limited number of pins to cover all test/trim functions, or in which only analog, no-connect, or failsafe pins are available for trim or test mode entry control or trim or test data input.