1263 results about "Scan chain" patented technology

An integrated circuit is provided with a scan chain including a scan flip-flop and a dummy block. The dummy block has a clock terminal receiving a clock signal, a scan input terminal connected to a scan data line within the scan chain, and a scan output terminal connected to another scan data line within the scan chain. The dummy block is configured to output data on the scan output terminal in response to input data fed to the scan input terminal, not responsively to the clock signal.

A test access control apparatus includes test access mechanism (TAM) buses and an extended IEEE 1149.1 Test Access Port (TAP) Controller. The TAM buses support memory built-in-self-test (BIST) circuit for the memory known-good-die (KGD) test, scan chains for the logic KGD test; and through-silicon-via (TSV) chains that are configured to conduct the TSV test that verifies any defect in vertical interconnects between any two chip layers of the stacked chip device. The TAP Controller is coupled to the TAM buses and is configured to control the memory KGD test, the logic KGD test and the TSV test between two chip layers. A cost-effective connection or configuration of test access control apparatus in 3D-IC is also present. In accordance with an embodiment of the present invention, a test access control method includes a yield-concerned test methodology for 3D-IC, and an integrated flow of test access control apparatus supporting heterogeneous test protocols of SOC

A scan test circuitry design imbedded on an SoC having the scan architecture of a VLCT platform is disclosed herein. This BIST circuitry design that is not limited in the number of scan test ports supported includes at least one scan chain group having a corresponding clock domain that couples to receive test stimulus data. Each scan chain group has a corresponding test mode signal to shift the test stimulus data at a shift clock rate derived from its corresponding clock domain. A controlling demultiplexer connects to each multiplexer unit within each scan chain group to provide control signals for shifting in the test stimulus. A clock control mechanism provides a control signal for each scan chain to shift test stimulus and capture resultant data. Furthermore, when a simultaneous test mode signal is enabled, the clock control mechanism couples to each scan chain to enable simultaneous capture of each scan chain group.

A shift scan chain includes logic circuit blocks 11-18 and scan registers 21-28 connected at stages succeeding them. The shift chain is divided into divisional chains including the scan registers 21-24 and the scan registers 25-28. In the test operation mode of a semiconductor integrated circuit, test input data TI are supplied in synchronism with a multiplied clock signal CKD at a frequency twice of that of a clock signal CK. The test input data TI are converted by a serial/parallel conversion circuit 40 into parallel data S41 and S42, which are respectively supplied to the head scan registers 21 and 25 of the corresponding divisional chains. The length of each divisional chains becomes ½, and a test time period can be shortened.

Electronic scan circuitry includes a decompressor (510), a plurality of scan chains (520.i) fed by the decompressor (510), a scan circuit (502, 504) coupled to the plurality of scan chains (520.i) to scan them in and out, a masking circuit (590) fed by the scan chains (520.i), and a scannable masking qualification circuit (550, 560, 580) coupled to the masking circuit (590), the masking qualification circuit (550, 560, 580) scannable by scan-in of bits by the decompressor (510) along with scan-in of the scan chains (520.i), and the scannable masking qualification circuit (550, 560, 580) operable to hold such scanned-in bits upon scan-out of the scan chains through the masking circuit (590). Other scan circuitry, processes, circuits, devices and systems are also disclosed.

In processors having a multicore, such as CMPs, an independent MISR test pattern compression circuit is provided for each logic block in a multicore processor such as a CMP comprising a plurality of processor cores makes it possible to perform LSI tests more efficiently. A processor comprises a plurality of logic block circuits, plurality of logic block circuits comprising at least a first processor core circuit and a second processor core circuit, each processor core circuit having a scan chain circuit and being operable independently, and a common block circuit having a scan chain circuit and a cache circuit that is shared by the first processor core circuits and the second processor core circuits, the processor further comprising, for each logic block, a test pattern generating circuit operable to generate a test pattern and input the test pattern to the scan chain of each logic block circuit, and a test pattern compression circuit operable to accept as input and compress the test pattern output by the scan chain of each logic block circuit.

A procedure and processor are disclosed for avoiding lengthy delays in debug procedures during access by a memory mapped peripheral device. The processor includes in-circuit emulation means comprising one or more scan chains or serially connected registers for access by an external host computer system. The procedure comprises:a) the host computer system carrying out a debug procedure via said scan chains, and selectively interrupting such debug procedure for access to a peripheral memory mapped device;b) the host computer system writing into an area or memory of the processor a program for reading and/or writing data at a specified memory location; andc) the host computer system causing said processor to run said program, and then to return to said debug procedure.In another aspect, in order to permit small debugging programs to run, in serial scan in circuit emulation processes, on a processor in a deeply embedded application where no program RAM is provided, the processor includes one or more chains of serially connected registers coupled to interface means for access by an external host to enable a serial scan procedure to be carried out, one such chain including a set of serially coupled registers for storing one or more processor instructions read into a set of registers through the interface means, and the processor including address means, for addressing program memory, coupled to said set of registers for addressing the set of registers, and means for reading the processor instructions in the set of registers to an instruction resister of the processor.

An integrated circuit device includes at least one functional module which outputs save data in synchronism with a saving clock signal, a power supply control unit which selects one of the functional modules, and controls stop and resumption of power supply to the selected functional module, a save data storage unit which stores save data output from a functional module selected by the power supply control unit, and an error checking and correction unit which performs error checking and correction for the save data stored in the save data storage unit when the save data is to be restored to the functional module in synchronism with a restoration clock signal.

Scan chains to support debugging and manufacturing test modes for integrated circuit chips are made adaptable. Scan chains may be configured either in a multiple scan chain JTAG mode or in a multiple independent and parallel scan chain mode. The configuration transition between the scan modes is made by private instructions implemented in a JTAG controller, which supports the IEEE 1149.1 standard.

A method for testing and diagnosing shift register latch chains coupled to logic circuits in an integrated circuit, the method including: (a) determining which of the shift register latch chains are failing by propagating a test pattern of zeros and ones through the shift register latch chains while gating which of the shift register latch chains contents are propagated into the means for generating a test signature; and (b) for each failing shift register latch chain: (b1) propagating a test pattern through the shift register latch chains while gating a selected sequential group of latches in a failing shift register latch to propagate into the means for generating a test signature; (b2) reducing the number of latches in the sequential group of latches; and (b3) repeating steps (b1) and (b2) until all failing latches of the failing shift register latch chain have been determined.

A scan test architecture is implemented. The scan test architecture provides a method of performing scan test of unbalanced scan chains. The scan test architecture generates a control signal (i.e., masking signal) to mask bits in an unbalanced scan chain. In one embodiment, the control signal is generated with a logic gate, a comparator, and a counter.

A method, system, and computer program product for identifying failures in multi-core processors, utilizing logic built-in self test (LBIST) technology. Multi-core processors, having LBIST and pseudo-random pattern generator (PRPG) circuitry, are tested. Controlled by the LBIST control logic, PRPG inputs a test pattern into scan chains within the cores of each device. A new test pattern is generated and executed during the scan shift phase of each LBIST loop. Logic output generated by each scan chain in the core is compared to other core logic output. Failures within the multi-core processors are determined by whether the logic output generated from a core, within a latch sequence, does not match the logic output of the other cores. If logic output, from a core within a latch sequence, does not match, then the latch number, loop number, and latch values are recorded as failed.

For use with a design database and a timing database, a computer implemented process for electronic design automation comprising: receiving a netlist that includes cells interconnected by circuit paths, wherein a plurality of the cells are scan cells connected in at least one scan chain; ordering the scan cells according to a prescribed scan cell ordering rule so as to produce a plurality of ordering relationships among scan cells; assigning respective weights from a first category of one or more weights to respective prescribed scan cell order relationships among scan cells of the netlist; assigning respective weights from a second category of one or more weights to prescribed circuit path relationships among cells of the netlist; and determining a physical placement of the cells of the netlist, including the scan cells, using a cost function that places the cells according to the assigned weights.

Systems, structures and methods for generating a test clock for scan chains to implement scan-based testing of electronic circuits are disclosed. In one embodiment, a test clock control structure includes a programmable test clock controller. The programmable test clock controller includes a test clock generator for generating a configurable test clock. It also includes a scan layer interface to drive a scan chain portion with the configurable test clock, and a control layer interface configured to access control information for controlling the scan chain portion. In another embodiment, a method effectuates scan-based testing of circuits. The method includes performing at least one intra-domain test and performing at least one inter-domain test using implementing dynamic fault detection test patterns, which can include last-shift-launch test patterns and broadside test patterns.

In one embodiment, an apparatus comprises a scan circuit including at least a first and a second clock domain and a scan chain having a first plurality of scan cells positioned in the first clock domain and a second plurality of scan cells positioned in the second clock domain. A scan clock source, coupled to the scan chain, generates a first scan clock signal to the first plurality of scan cells and a second scan clock signal to the second plurality of scan cells. The first and the second clock signals have an inverted relationship.

A semiconductor integrated circuit includes a target circuit with at least a scan chain having sub scan chains of stages to sequentially shift a test data in response to a clock signal in a scan path test mode, and each of the sub scan chains includes first flip-flops connected in series. A backup control circuit controls the target circuit and a memory such that a plurality of sub internal state data of a data indicating an internal state of the target circuit are stored as a plurality of write data in the memory in a save mode through the sub scan chains and the plurality of sub internal state data are read out from the memory as a plurality of read data and set in the sub scan chains in a restore mode.

An integrated circuit including embedded test functionality. An integrated circuit may include a plurality of processor cores each configured to execute instructions, and a test access port configured to interface circuits included within the integrated circuit with a test environment external to the integrated circuit for testing of the circuits. The test access port may include virtualization logic configured to allow a first set of instructions executing on the given processor core to control activity of the test access port for testing of the circuits. In one embodiment, the circuits may be accessible for testing via a plurality of scan chains, wherein the scan chains and the test access port are compliant with a version of Joint Test Access Group (JTAG) standard IEEE 1149, and wherein the test access port includes a Test Data In (TDI) pin, a Test Data Out (TDO) pin, and a Test Clock (TCK) pin.

A test clock controller for generating a test clock signal for scan chains in integrated circuits having one or more clock domains, comprises a shift clock controller for generating a shift clock signal for use in loading test patterns into scan chains in the clock domains and for unloading a test response patterns from the scan chains and for generating a burst phase signal after loading a test pattern; and a burst clock controller associated with each of one or more clock domains and responsive to a burst phase signal for generating a burst of clock pulses derived from a respective reference clocks and including a first group of burst clock pulses having a selected reduced frequency relative to the reference clock and a second group of burst clock pulses having a frequency corresponding to that of the reference clock.