A method for checking a Design for Test (DFT) circuit includes: transmitting a control signal to the DFT circuit to determine test mode signals output by the DFT circuit, with the DFT circuit being configured to sequentially select multiple address latches according to the control signal to output the test mode signals; analyzing the test mode signals to determine whether the multiple address latches in the DFT circuit have an error; and outputting a simulation result report.

This disclosure provides methods and apparatuses for testing a tested circuit. In an implementation, a chip test circuit transmits input data of a test vector to a data distribution circuit through an input of a test bus, and transmits the input data of the test vector to a scan input channel of a tested circuit through the data distribution circuit. After scanning of the tested circuit ends, output data of the test vector of the scan output channel of the tested circuit is transmitted to an output of the test bus through the data distribution circuit to complete the test of the tested circuit. A dynamic correspondence between the data distribution circuit and the test bus is implemented by configuring a first selector, so that test resources can be dynamically allocated.

A system includes test control circuitry and a memory. The memory includes a memory array, a pre-decode circuit, and a plurality of address latches. Each address latch of the plurality of address latches is configured to operate in a scan chain of a plurality of scan chains for scan testing. A first set of the plurality of address latches each has a data input coupled to a corresponding address pin of the first memory and each has an output coupled to the pre-decode circuit. A second set of the plurality of address latches, mutually exclusive of the first set, each has a data input coupled to a data input of at least one latch in the first set of the plurality of latches and each is configured to not provide any input to the pre-decode circuit.

An address and command port interface selectively enables JTAG TAP domain operations and Trace domain operations within an IC. The port carries TMS and TDI input and TDO output on a single pin and receives a clock signal on a separate pin. The addressable two pin interface loads and updates instructions and data to the TAP domain within the IC. The instruction or data update operations in multiple ICs occur simultaneously. A process transmits data from an addressed target device to a controller using data frames, each data frame comprising a header bit and data bits. The logic level of the header bit is used to start, continue, and stop the data transmission to the controller. A data and clock signal interface between a controller and multiple target devices provides for each target device to be individually addressed and commanded to perform a JTAG or Trace operation.

An address and command port interface selectively enables JTAG TAP domain operations and Trace domain operations within an IC. The port carries TMS and TDI input and TDO output on a single pin and receives a clock signal on a separate pin. The addressable two pin interface loads and updates instructions and data to the TAP domain within the IC. The instruction or data update operations in multiple ICs occur simultaneously. A process transmits data from an addressed target device to a controller using data frames, each data frame comprising a header bit and data bits. The logic level of the header bit is used to start, continue, and stop the data transmission to the controller. A data and clock signal interface between a controller and multiple target devices provides for each target device to be individually addressed and commanded to perform a JTAG or Trace operation.

The present disclosure describes a novel method and apparatus for using a device's power and ground terminals as a test and/or debug interface for the device. According to the present disclosure, messages are modulated over DC voltages applied to the power terminals of a device to input test/debug messages to the device and output test/debug messages from the device. The present disclosure advantageously allows a device to be tested and/or debugged without the device having any shared or dedicated test or debug interface terminals.

An address and command port interface selectively enables JTAG TAP domain operations and Trace domain operations within an IC. The port carries TMS and TDI input and TDO output on a single pin and receives a clock signal on a separate pin. The addressable two pin interface loads and updates instructions and data to the TAP domain within the IC. The instruction or data update operations in multiple ICs occur simultaneously. A process transmits data from an addressed target device to a controller using data frames, each data frame comprising a header bit and data bits. The logic level of the header bit is used to start, continue, and stop the data transmission to the controller. A data and clock signal interface between a controller and multiple target devices provides for each target device to be individually addressed and commanded to perform a JTAG or Trace operation.

Methods, systems, and apparatus for testing semiconductor devices.

Existing multi-wire debugging protocols, such as 4-wire JTAG, 2-wire cJTAG, or ARM SWD, are run through a serial wireless link by providing the debugger and the target device with hardware interfaces that include UARTs and conversion bridges. The debugger interface serializes outgoing control signals and de-serializes returning data. The target interface de-serializes incoming control signals and serializes outgoing data. The actions of the interfaces are transparent to the inner workings of the devices, allowing re-use of existing debugging software. Compression, signal combining, and other optional enhancements increase debugging speed and flexibility while wirelessly accessing target devices that may be too small, too difficult to reach, or too seal-dependent for a wired connection.

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. In a fifth aspect of the present disclosure, an interface select circuit, FIGS. 41-49, provides for selectively using either the 5 signal interface of FIG. 41 or the 3 signal interface of FIG. 8.