Nxp Usa, Inc.

Freescale Semiconductor,inc.

Wanggen Zhang

Shayan Zhang

Ling Wang

Huangsheng Ding

Xu Zhang

Sian Lu

Wei Zhang

Jianzhou Wu

Yizhong Zhang

Hao Wang

Yin Guo

Chao Liang

Xiuqiang Xu

Yifeng Liu

Weiwei Sang

Song Huang

Guoping Wan

Pingli Hao

Chad J Lerma

Kai Liu

Zhou Fang

An integrated circuit operable in a scan mode includes a scan chain formed by cascaded flip-flop cells. Each flip-flop cell includes a master latch that receives a first data signal and generates a first latch signal, a slave latch that receives the first latch signal and generates a second latch signal, and a multiplexer having first and second inputs respectively connected to the master and slave latches that receives a first input signal and the second latch signal, and generates a scan data output signal depending on an input trigger signal. The first input signal is one of the first data signal and the first latch signal. The clock signal provided to the slave latch is gated by the input trigger signal.

Integrated circuit with low power scan system

An integrated circuit operable in a scan mode includes a scan chain formed by cascaded flip-flop cells. Each flip-flop cell includes a master latch that receives a first data signal and generates a first latch signal, a slave latch that receives the first latch signal and generates a second latch signal, and a multiplexer having first and second inputs respectively connected to the master and slave latches for receiving a first input signal and the second latch signal, and generating a scan data output signal depending on a trig signal. The first input signal is one of the first data signal and the first latch signal. The clock signal provided to the slave latch is gated by the trig signal.

An integrated circuit senses attempts to access security-related data stored in registers connectable into a scan chain when the attempt includes locally and selectively asserting a scan-enable signal at a corresponding branch of the scan-enable tree when the integrated circuit is in a secure functional mode. When such an attempt is detected, the integrated circuit (i) generates a security warning that causes a reset of the security-related data and/or (ii) engages a bypass switch to disconnect the scan chain from the respective output terminal to preclude the security-related data from being shifted out of the IC via the scan chain.

Integrated circuit with secure scan enable

An integrated circuit (IC) having a memory for storing data also has a memory built in self-test (MBIST) unit coupled to the memory for testing an operation of the memory. A test interface provides test data. Flip-flops of the IC are connected together into at least one serial scan chain. The test interface unit receives test data including MBIST configuration data. The MBIST unit, in a first mode, tests the memory based on the MBIST configuration data at least partly in parallel with a scan test using the scan chain. Thus, both the memory and the logic circuitry can be tested in parallel.

Method and apparatus for testing integrated circuit

A built-in-self-test (BIST) circuit is connected to a processor and a sigma-delta modulator (SDM) and includes an averaging circuit, a reference signal generator, and a comparator. The averaging circuit calculates an average of a sum of a set of bit signals of the SDM output signal over a period of time period, and generates an average SDM signal. The reference signal generator generates a reference SDM signal based on an SDM input signal. The comparator compares the voltage levels of the average SDM and reference SDM signals with a threshold value, and generates a test output signal based on the comparison.

Built-in-self-test circuit for sigma-delta modulator

An integrated circuit that includes a processor also has an on-chip current test circuit that indirectly measures quiescent current in the processor. A supply voltage pin of the integrated circuit receives a supply voltage from an external test unit to provide power to the processor. The on-chip test circuit measures a voltage change across the processor during a predetermined test period T when the processor is isolated from the supply voltage and the clock signal is stopped. The voltage change provides an indication of quiescent current corresponding to the processor.

On-chip current test circuit

Test circuitry for an integrated circuit (IC) that has a scan chain includes a control unit for applying a test pattern and a clock signal to the scan chain, and for varying the level of a supply voltage during a scan test procedure. In a first test phase, the supply voltage is set to the rated voltage level of the IC while a test pattern is shifted into the scan chain at a fast rate. A second, capture phase is run at a lower rate and the supply voltage is reduced to a lower level such that defects that cannot be detected when the capture phase is run at the rated voltage are observable yet switching elements in the IC still function correctly. Running the shift phase at the higher speed reduces the overall test time compared with known very low voltage (VLV) scan test procedures.

Test circuit for very low voltage and bias scan testing of integrated circuit

A digital decoder, used in a reconfigurable circuit, for decoding digital pulses includes a phase indicator module having inputs coupled to a reference pulse input and a data pulse input. The phase indicator module has timing information outputs that provide logic values indicative of rising and falling edges of pulses occurring on the reference pulse input and the data pulse input. A phase decoder module has inputs coupled to the timing information outputs, and outputs decoded binary data values. In operation, the phase decoder module compares at least two of the logic values at the timing information outputs with a signal representative leading and trailing edges of a pulse applied to one of the phase inputs to determine a pulse arrival order sequence on the phase inputs and thereby provide the decoded binary data values.

Reconfigurable circuit and decoder therefor

A system for performing a scan test on an integrated circuit such as a System on a Chip (SoC) that may be packaged in different package types and with different features enabled includes a bypass-signal generator and a first scan-bypass circuit. The bypass-signal generator generates a first bypass signal based on chip package information. The first bypass signal indicates whether a first scan chain associated with a first non-common circuit block of the SoC is to be bypassed. The first scan chain is bypassed in response to the first bypass signal. By enabling partial scan testing based on package information, unintentional yield loss caused by a full scan test determining an SoC is faulty can be avoided.

System and method for performing scan test

A low power scan flip-flop cell includes a multiplexer, a master latch, a scan slave latch and a data slave latch. The master latch is connected to the multiplexer, and used for generating a first latch signal. The scan slave latch is connected to the master latch, and generates a scan output (SO) signal. The data slave latch is connected to the master latch, and generates a Q output depending on a scan enable (SE) input signal and the first latch signal. The Q output is maintained at a predetermined level during scan mode, which eliminates unnecessary switching of combinational logic connected to the scan flip-flop cell and thus reduces power consumption.

Low power scan flip-flop cell

A reconfigurable integrated circuit (IC) has IC interface terminals including circuit input terminals and circuit output terminals. A bypass controller and bypass circuitry are coupled to each other, and to at least one of the circuit input terminals and at least one of the circuit output terminals. A processing circuit has multiple circuit modules coupled to the bypass circuitry. The processing circuit is coupled to at least one of the circuit input terminals and at least one of the circuit output terminals. In operation the bypass controller controls the bypass circuitry to selectively couple at least one pair of the IC interface terminals together, the pair including one of the circuit input terminals and one of the circuit output terminals. When the pair of IC interface terminals are coupled together, at least one of the circuit modules is selectively de-coupled from the pair of the IC terminals.

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Wanggen Zhang