Testing of integrated circuits is achieved by a test architecture utilizing a scan frame input shift register, a scan frame output shift register, a test controller, and a test interface comprising a scan input, a scan clock, a test enable, and a scan output. Scan frames input to the scan frame input shift register contain a test stimulus data section and a test command section. Scan frames output from the scan frame output shift register contain a test response data section and, optionally, a section for outputting other data. The command section of the input scan frame controls the test architecture to execute a desired test operation.

A system includes a multiple input signature register (MISR) to receive outputs from M different scan chains in response to N test patterns applied to test an integrated circuit. The MISR provides N test signatures for the integrated circuit based on the outputs of the M different scan chains generated in response to each of the N test patterns. Each of the scan chains holds one or more test data bits that represent behavior of the integrated circuit in response to each of the N test patterns. A shift register is loaded from an interface and holds one of N comparison signatures that is used to validate a respective one of the N test signatures generated according to a given one of the N test patterns. A comparator compares each of the N test signatures with a respective one of the N comparison signatures to determine a failure condition based on the comparison.

The disclosure provides a novel method and apparatus for inputting addresses to devices to select the device TAP for access. Further, the disclosure provides a novel method and apparatus for inputting addresses for selecting device TAPs and for inputting commands for commanding circuitry within the device. The inputting of addresses or the inputting of addresses and commands is initiated by a control bit input on TDI that is recognized during the Run Test/Idle, Pause-DR or Pause-IR TAP states.

The disclosure describes novel methods and apparatuses for accessing test compression architectures (TCA) in a device using either a parallel or serial access technique. The serial access technique may be controlled by a device tester or by a JTAG controller. Further the disclosure provides an approach to access the TCA of a device when the device exists in a daisy-chain arrangement with other devices, such as in a customer's system. Additional embodiments are also provided and described in the disclosure.

Techniques and mechanisms to exchange test, debug or trace (TDT) information via a general purpose input/output (I/O) interface. In an embodiment, an I/O interface of a device is coupled to an external TDT unit, wherein the I/O interface is compatible with an interconnect standard that supports communication of data other than any test information, debug information or trace information. One or more circuit components reside on the device or are otherwise coupled to the external TDT unit via the I/O interface. Information exchanged via the I/O interface is generated by, or results in, the performance of one or more TDT operations to evaluate the one or more circuit components. In another embodiment, the glue logic of the device interfaces the I/O interface with a test access point that is coupled between the one or more circuit components and the I/O interface.

A system and method are provided on one or more companion chips having a plurality of cores. Each core has core circuitry and a test interface for carrying out tests in relation to the core circuitry. The test interface has an address register to hold an address of the core and address determination circuitry. The address determination circuitry is configured to compare an address received on an address line to the address held in the address register to determine whether a core is being addressed. The address determination circuitry is also configured to direct the test interface to carry out a testing operation in response to the determination.

In some examples, an integrated circuit comprises: a TDI input, a TDO output, a TCK input and a TMS input; a TAP state machine (TSM) having an input coupled to the TCK input, an input coupled to the TMS input, an instruction register control output, a TSM data register control (DRC) output, and a TSM state output; an instruction register having an input coupled to the TDI input, an output coupled to the TDO output, and a control input coupled to the instruction register control output of the TAP state machine; router circuitry including a TSM DRC input coupled to the TSM DRC output, a control DRC input coupled to the TSM state output, and a router DRC output; and a data register having an input coupled to the TDI input, an output coupled to the TDO output, and a data register DRC input coupled to the router DRC output.

A method for detecting a deterioration state in an elevator suspension member including electrically conductive cords uses a multiplexing unit (MU) to apply first and second alternating voltages to proximal ends of first and second groups of the cords respectively and connect the proximal end of a third group of the cords to a voltage measurement arrangement connected to a reference potential. Distal ends of the groups are connected together. A first neutral point voltage between the third proximal end and the reference potential is determined. The MU is switched to apply the first alternating voltage to the second proximal end, apply the second alternating voltage to the third proximal end and determine a second neutral point voltage between the first proximal end and the reference potential. The deterioration state of the suspension member arrangement is determined based on the first and second neutral point voltages.

An integrated circuit includes first and second data storage circuits, first, second, and third shadow storage circuits, and first, second, and third multiplexer circuits. The first multiplexer circuit is configurable to provide a state of a data signal from the first data storage circuit to the first shadow storage circuit in a snapshot mode. The second multiplexer circuit is coupled between an output of the second data storage circuit and an input of the second shadow storage circuit. The third multiplexer circuit is coupled to the second multiplexer circuit. The third multiplexer circuit is configurable to provide a state of an output signal of the first shadow storage circuit to an input of the third shadow storage circuit in a scan mode bypassing the second shadow storage circuit.

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.