Abstract: We report methods relating to scan warmup of integrated circuit devices. One such method may comprise loading a scan test stimulus to and unloading a scan test response from a first set of logic elements of an integrated circuit device at a scan clock first frequency equal to a test clock frequency; adjusting the scan clock from the first frequency to a second frequency by a scan warmup unit, wherein the scan clock second frequency is equal to a system clock frequency; and capturing the scan test response by a shift logic at the scan clock second frequency. We also report processors containing components configured to implement the method, and fabrication of such processors. The methods and their implementation may reduce di/dt events otherwise commonly occurring when testing logic elements of integrated circuit devices.

Abstract: Scan-based reset utilizes already existing design-for-test scan chains to reset control and logic circuitry upon reset conditions, such as power-up reset. Such utilization eliminates the need for expensive, high fan-out reset trees and per scan cell reset control logic, thus reducing chip area and power consumption. Additional power savings is achieved by controlling clock frequency during reset conditions. Limiting scan cell chain length and providing multiple chains reduces reset latency.

Abstract: We report methods relating to scan warmup of integrated circuit devices. One such method may comprise loading a scan test stimulus to and unloading a scan test response from a first set of logic elements of an integrated circuit device at a scan clock first frequency equal to a test clock frequency; adjusting the scan clock from the first frequency to a second frequency by a scan warmup unit, wherein the scan clock second frequency is equal to a system clock frequency; and capturing the scan test response by a shift logic at the scan clock second frequency. We also report processors containing components configured to implement the method, and fabrication of such processors. The methods and their implementation may reduce di/dt events otherwise commonly occurring when testing logic elements of integrated circuit devices.

Abstract: A method, computer program storage device and apparatus are provided for flexible observability during a scan. In one aspect of the present invention, a method is provided. The method includes providing a selector load input to at least a portion of a scan chain, selecting an observe-only scan mode for the at least a portion of the scan chain based at least upon the selector load input, and providing a data input to a storage element in the scan chain based at least upon the observe-only scan mode. The apparatus includes a first scan chain multiplexor comprising a selector input, a first input terminal, a second input terminal and an output terminal. The apparatus also includes a first scan chain storage element comprising an input terminal and an output terminal, where the input terminal of the first scan chain storage element is communicatively coupled to the output terminal of the first scan chain multiplexor.

Abstract: A method, computer program storage device and apparatus are provided for flexible observability during a scan. In one aspect of the present invention, a method is provided. The method includes providing a selector load input to at least a portion of a scan chain, selecting an observe-only scan mode for the at least a portion of the scan chain based at least upon the selector load input, and providing a data input to a storage element in the scan chain based at least upon the observe-only scan mode. The apparatus includes a first scan chain multiplexor comprising a selector input, a first input terminal, a second input terminal and an output terminal. The apparatus also includes a first scan chain storage element comprising an input terminal and an output terminal, where the input terminal of the first scan chain storage element is communicatively coupled to the output terminal of the first scan chain multiplexor.

Abstract: Scan-based reset utilizes already existing design-for-test scan chains to reset control and logic circuitry upon reset conditions, such as power-up reset. Such utilization eliminates the need for expensive, high fan-out reset trees and per scan cell reset control logic, thus reducing chip area and power consumption. Additional power savings is achieved by controlling clock frequency during reset conditions. Limiting scan cell chain length and providing multiple chains reduces reset latency.

Abstract: A method and apparatus for a structure of a flip-flop that is tolerant to the noise pulses occurring due to the presence of crosstalk faults by sampling the input data multiple times before and after the active clock edge. The final stored value at the flip-flop is determined by the resolution of a counter circuit residing in the flip-flop, which is activated at the change of the sampled input data. This counter based resolution mechanism allows for the detection and filtering of the noise pulse induced at the input of the flip-flop due to a crosstalk fault.

Abstract: A register designed to detect and correct soft errors in real time. A redundant latch is added to the existing structure of a flip flop and functional data is simultaneously registered at multiple latches. The content of these multiple latches are fed to a majority voting circuit. If the content of any of these latches is corrupted by soft error, it is filtered out through the majority voting circuit and correct data is passed out from the output of the flip flop. In one embodiment, this design operates as a simple scan flip flop or scan-hold flip flop, and is useful for system testability purposes.

Abstract: A register designed to detect and correct soft errors in real time. A redundant latch is added to the existing structure of a flip flop and functional data is simultaneously registered at multiple latches. The content of these multiple latches are fed to a majority voting circuit. If the content of any of these latches is corrupted by soft error, it is filtered out through the majority voting circuit and correct data is passed out from the output of the flip flop. In one embodiment, this design operates as a simple scan flip flop or scan-hold flip flop, and is useful for system testability purposes.

Abstract: A method and apparatus for a structure of a flip-flop that is tolerant to the noise pulses occurring due to the presence of crosstalk faults by sampling the input data multiple times before and after the active clock edge. The final stored value at the flip-flop is determined by the resolution of a counter circuit residing in the flip-flop, which is activated at the change of the sampled input data. This counter based resolution mechanism allows for the detection and filtering of the noise pulse induced at the input of the flip-flop due to a crosstalk fault.