A semiconductor integrated circuit to receive a test scan input, a test clock, and a test mode signal and output a secure scan output signal, the integrated circuit including: a secure key circuit to generate delay input signals, which are differently delayed from the test scan input, and to generate an input key signal by capturing the delay input signals in response to the test clock; a key comparator to generate a verification result indicating whether an input key of the input key signal is identical with a preset reference key; a chip to generate a scan output signal based on the test scan input; a scan output remapper to obfuscate the scan output signal according to the verification result and to output the obfuscated scan output signal as the secure scan output signal; and a secure scan controller to control the secure key circuit, key comparator, chip, and remapper.

A circuit comprises a plurality of clock control devices. Each of the clock control devices is configured to generate a scan test clock signal for a particular clock domain in the circuit and comprises circuitry configured to select clock pulses of a fast clock signal as scan capture clock pulses for the particular clock domain based on a particular clock pulse of a slow clock signal and a scan enable signal. The order and spacing between the groups of the scan capture clock pulses for different clock domains correspond to the order and spacing of the clock pulses of the slow clock signal.

Testing of an electrical device is achieved by providing a test access mechanism within the device that can receive scan frames from an external tester. The received scan frames contain stimulus data to be applied to circuitry within the device to be tested, a command for enabling a test control operation, and a frame marker bit to indicate the end of the scan frame pattern. The inputting of scan frames can occur continuously and simultaneous with a commanded test control operation.

A system comprises a memory sub-system controller mounted to a printed circuit board (PCB) and an in-circuit test (ICT) device. The memory sub-system controller has test points on the PCB comprising stimulus points and observation points. The ICT device connects to the test points of the controller. The ICT device converts automated test pattern generation (ATPG) input test vectors to test signals. A first set of pin drivers of the ICT device applies the test signals to the stimulus points of the controller and a second set of pin drivers of the ICT device read output signals output at the observation points of the controller. A comparator of the ICT device compares the output signals with output test vectors. The comparator provides test result data comprising a result of the comparison.

A system includes a test access port (TAP) configured to provide internal joint test action group (IJTAG) access to one or more test data registry (TDR). The system further includes a plurality of hierarchical electronic components, wherein each hierarchical electronic component includes a de-asserted segment inserted bit (D-SIB) register, an asserted segment inserted bit (A-SIB) register, and a TDR associated with the D-SIB register. Each D-SIB register is configured to prevent access to its associated TDR when a reset signal is asserted and each A-SIB register is configured to provide access to its subsequent A-SIB register or D-SIB register coupled thereto when the reset signal is asserted.

A boundary scan test method and a storage medium are disclosed. The method can be capable of testing the connectivity of a pad having a direct connection to user logic. The method is preformed based on a scan test instruction to FPGA. According to the method of the invention, software configuration is performed in FPGA user logic with respect to a PAD to be tested, such that the PAD can be tested according to the configuration without the need to test or pass through PADs that do not need to be tested. The method shortens boundary scan chains, thereby enabling rapid and flexible boundary scan tests and improving test efficiency.

A method of updating firmware in a chip in a stable and effective manner receives firmware outputted by a controller. The received firmware is burned into the chip. A voltage level of a controlling signal outputted by a controlling pin of the chip is latched to a certain level based on a latching signal at a first voltage level outputted by the controller. The storage medium is refreshed for making the burned firmware effective based on refresh instruction outputted by the controller. The latching signal at a second voltage level for unlatching the voltage level of the controlling signal is outputted by the controller if operations of the chip are stable. An updating operation of the chip by the method does not interrupt other operations being executed by the chip. A firmware updating apparatus and a computer readable storage medium applying the method are also disclosed.

A method of updating firmware in a chip in a stable and effective manner receives firmware outputted by a controller. The received firmware is burned into the chip. A voltage level of a controlling signal outputted by a controlling pin of the chip is latched to a certain level based on a latching signal at a first voltage level outputted by the controller. The storage medium is refreshed for making the burned firmware effective based on refresh instruction outputted by the controller. The latching signal at a second voltage level for unlatching the voltage level of the controlling signal is outputted by the controller if operations of the chip are stable. An updating operation of the chip by the method does not interrupt other operations being executed by the chip. A firmware updating apparatus and a computer readable storage medium applying the method are also disclosed.

A method of loading a data string into a Joint Test Action Group (JTAG) shift register is provided. The method includes determining whether the last bit of the data string is equal to one or zero. In response to determining that the last bit is equal to one, the method includes simultaneously setting each flip-flop of the shift register to one, identifying first data string loading bits by removing, from the data string, the last bit and any other bits in a continuous sequence of bits, including the last bit, that are each equal to one, and sequentially loading the identified first data string loading bits into the shift register. A testing apparatus for performing the method and an enhanced JTAG interface are also provided. The method, testing apparatus, and enchanced JTAG interface may reduce the number of clock cycles required to load the shift register.

Testing of die on wafer is achieved by; (1) providing a tester with the capability of externally communicating JTAG test signals using simultaneously bidirectional transceiver circuitry, (2) providing die on wafer with the capability of externally communicating JTAG test signals using simultaneously bidirectional transceiver circuity, and (3) providing a connectivity mechanism between the bidirectional transceiver circuitry's of the tester and a selected group or all of the die on wafer for communication of the JTAG signals.