A first clock signal and second clock signal are generated by first and second clock circuits, respectively. A multiplexer selects between the first clock signal and second clock signal to produce a scan clock signal. A non-scan flip flop clocks a data input through to a data output in response to the second clock signal. A scan chain includes a scan flip flop configured to capture the data output from the non-scan flip flop in response to the scan clock signal. The logic state of the captured data in the scan flip flop of the scan chain is indicative of whether the second clock circuit has a stuck-at fault condition (for example, with respect to any one or more included buffer circuits).

An integrated circuit (IC) includes first and scan latches that are enabled to load data during a first part of a clock period. A clocking circuit outputs latch clocks with one latch clock driven to an active state during a second part of the clock period dependent on a first address input. A set of storage elements have inputs coupled to the output of the first scan latch and are respectively coupled to a latch clock to load data during a time that their respective latch clock is in an active state. A selector circuit is coupled to outputs of the first set of storage elements and outputs a value from one output based on a second address input. The second scan latch then loads data from the selector's output during the first part of the input clock period.

A method comprises a system comprising a host device coupled to a first remote device actively operating according to a state diagram that the host device and all remote devices follow during operation of the system. The method further comprises powering up a second remote device while the host device and first remote device are actively operating according to the state diagram. The second remote device waits for a synchronization point sequence. Upon detecting the synchronization point sequence, the second remote device implements a predetermined feature set and synchronizes itself to the state diagram at a common point as the host device and first remote device.

A method comprises a system comprising a host device coupled to a first remote device actively operating according to a state diagram that the host device and all remote devices follow during operation of the system. The method further comprises powering up a second remote device while the host device and first remote device are actively operating according to the state diagram. The second remote device waits for a synchronization point sequence. Upon detecting the synchronization point sequence, the second remote device implements a predetermined feature set and synchronizes itself to the state diagram at a common point as the host device and first remote device.

This disclosure describes a reduced pin bus that can be used on integrated circuits or embedded cores within integrated circuits. The bus may be used for serial access to circuits where the availability of pins on ICs or terminals on cores is limited. The bus may be used for a variety of serial communication operations such as, but not limited to, serial communication related test, emulation, debug, and/or trace operations of an IC or core design. Other aspects of the disclosure include the use of reduced pin buses for emulation, debug, and trace operations and for functional operations.

This disclosure describes a reduced pin bus that can be used on integrated circuits or embedded cores within integrated circuits. The bus may be used for serial access to circuits where the availability of pins on ICs or terminals on cores is limited. The bus may be used for a variety of serial communication operations such as, but not limited to, serial communication related test, emulation, debug, and/or trace operations of an IC or core design. Other aspects of the disclosure include the use of reduced pin buses for emulation, debug, and trace operations and for functional operations.

An error rate measuring apparatus that measures whether or not an FEC operation of the device under test is possible based on a comparison result of the signal received from the device under test and a test signal includes an operation unit that sets a codeword length and an FEC symbol length of the FEC corresponding to a communication standard of the device under test, a data comparison unit that compares bit string data obtained by converting the signal received from the device under test with error data to detect an FEC symbol error of each FEC symbol length, a display unit that associates the bit string data of the FEC symbol length as one point with one unit region of a display region and performs color-coding display depending on presence or absence of occurrence of the FEC symbol error by each FEC symbol length.

An error rate measuring apparatus that measures whether or not an FEC operation of the device under test is possible based on a comparison result of the signal received from the device under test and a test signal includes an operation unit that sets a codeword length and an FEC symbol length of the FEC corresponding to a communication standard of the device under test, a data comparison unit that compares bit string data obtained by converting the signal received from the device under test with error data to detect an FEC symbol error of each FEC symbol length, a display unit that associates the bit string data of the FEC symbol length as one point with one unit region of a display region and performs color-coding display depending on presence or absence of occurrence of the FEC symbol error by each FEC symbol length.

A semiconductor device includes a plurality of first micro-bumps suitable for transferring normal signals; a plurality of a second micro-bumps suitable for transferring test signals; and a test circuit including a plurality of scan cells respectively corresponding to the first and second micro-bumps. The test circuit is suitable for applying signals stored in the respective scan cells to the first and second micro-bumps, feeding back the applied signals from the first and second micro-bumps to the respective scan cells, and sequentially outputting the signals stored in the scan cells to a test output pad.

A semiconductor device includes a plurality of first micro-bumps suitable for transferring normal signals; a plurality of a second micro-bumps suitable for transferring test signals; and a test circuit including a plurality of scan cells respectively corresponding to the first and second micro-bumps. The test circuit is suitable for applying signals stored in the respective scan cells to the first and second micro-bumps, feeding back the applied signals from the first and second micro-bumps to the respective scan cells, and sequentially outputting the signals stored in the scan cells to a test output pad.