Abstract: A semiconductor memory device, having a test mode and a normal mode, includes a frequency multiplier and a test command sequence generator. The frequency multiplier receives a test clock signal in the test mode and generates multiple internal test clock signals, each of which has a frequency equal to a frequency of an operation clock signal in the normal mode. The test clock signal has a frequency lower than the frequency of the operation clock signal. The test command sequence generator generates at least one command signal in response to the internal test clock signals in the test mode. The at least one command signal corresponds to at least one operation timing parameter of the semiconductor memory device that is to be measured. The frequency multiplier may include a Phase Locked Loop (PLL) or a Delay Locked Loop (DLL).

Abstract: The present invention provides a method and system for improving memory testing efficiency, raising the speed of memory testing, detecting memory failures occurring at the memory operating frequency, and reducing data reported for redundancy repair analysis. The memory testing system includes a first memory tester extracting failed memory location information from the memory at a higher memory operating frequency, an external memory tester receiving failed memory location information at a lower memory tester frequency, and an interface between the first memory tester and the external memory tester. The memory testing method uses data strobes at the memory tester frequency to clock out failed memory location information obtained at the higher memory operating frequency. In addition, the inventive method reports only enough information to the external memory tester for it to determine row, column and single bit failures repairable with the available redundant resources.

Abstract: A method includes obtaining an equivalent core of multiple cores in a System-on-Chip circuit, and applying linear-feedback shift register LFSR reseeding for compressing test data of the equivalent core.

Abstract: The present invention assesses memory (DIMM) strength by calculating frequency content of a radiated field which is collected by an apparatus, such as a dipole antenna. Radiated field is created by accelerated charge, which is a function of the slew rate or DIMM strength. Radiated power is directly proportional to the frequency at which bits are driven. By separating the radiated field from the near field or stored field, the DIMM strength content is isolated from other functional DIMM issues, such as tRCD latency, refresh cycles, addressing mode, etc. By examining the radiated power, the disadvantages of the prior art, such as by probing the DIMM's contacts, are avoided.

Abstract: A method and apparatus is provided for detecting random access memory (RAM) failure for data with a plurality of addresses. The method comprises generating a plurality of RAM test patterns in a predetermined order, implementing a RAM test pattern on each data address in an initial testing pass, based on the predetermined order of the RAM test patterns, rotating the RAM test patterns sequentially to prepare for a new testing pass, and implementing the RAM test patterns on different data addresses in the new testing pass. The apparatus comprises means for generating a plurality of RAM test patterns in a predetermined order, means for implementing a RAM test pattern on each data address in an initial testing pass, based on the predetermined order of the RAM test patterns, means for rotating the RAM test patterns sequentially to prepare for a new testing pass, and means for implementing the RAM test patterns on different data addresses in the new testing pass.

Abstract: Methods and apparatuses for enabling a redundant memory element (20) during testing of a memory array (14). The memory array (14) includes general memory elements (18) and redundant memory elements (20). The general memory elements (18) are tested and any defective general memory elements (18) are replaced with redundant memory elements (20). The redundant memory elements (20) are tested only when they are enabled.

Abstract: A method for optimizing a scan chain ordering in circuit designs in an electronic computer-aided design system is provided.

Abstract: An apparatus for selectively implementing launch-off-scan capability in at-speed testing of integrated circuit devices includes a control device configured to selectively disable a master clock signal of a latch structure under test such that a pulse sequence of a system clock signal results in a slave-master-slave clock pulse sequence in the latch structure under test; wherein the control device utilizes the system clock signal as an input thereto and operates in a self-resetting fashion that is timing independent with respect to a scan chain.

Abstract: A system for receiving Joint Task Action Group (JTAG) data bits from a device under test includes a deserializer that receives serial messages from the device under test and forms data frames based on the serial messages. A frame sync module communicates with the deserializer and forms JTAG data bits based on the data frames. N virtual JTAG test access ports (VTAPs), each having an input and an output. The N VTAPs are connected in a daisy chain and the input of a first VTAP receives the JTAG data bits from the frame sync module.

Abstract: A test circuit arrangement for testing latch units is provided which includes a) a voltage generator configured to adjust a voltage potential difference between a first ground line and a second ground line of the latch units and/or to adjust a voltage potential difference between a first supply voltage line and a second supply voltage line of the latch units; b) combiner configured to combine logical outputs of the latch units; and c) determiner configured to determine the voltage potential difference between the first ground line and the second ground line and/or the voltage potential difference between the first supply voltage line and the second supply voltage line in a state when all of the latch units have identical logical outputs.

Abstract: An I/O compression apparatus, for testing a memory array and/or a logic circuit, is comprised of a selectable compression circuit that outputs compressed test data from the memory array/logic circuit. An I/O scan register is coupled to each I/O pad for converting serial data to parallel and parallel data to serial in response to a test mode select signal, a test data input, and a test clock.

Abstract: A boundary scan technique to generate toggling waveform such as a square wave signal to perform structural testing is disclosed. An instr_extesttoggle command is provided that enables IEEE 1149.1 boundary scan cell to selectively generate the toggling signal on the pre-specified output pads of the integrated circuit. The frequency of the toggling signal may be controlled by the JTAG clock signal and the frequency of the toggling signal may be independent of the length of the boundary scan chain. Such an approach circumvents provisioning test points on the interconnects of a printed circuit board.

Abstract: SRAM macro sparing allows for full chip function despite the loss of one or more SRAM macros. The controls and data flow for any single macro within a protected group are made available to the spare or spares for that group. This allows a defective or failed SRAM macro to be shut off and replaced by a spare macro, dramatically increasing manufacturing yield and decreasing field replacement rates. The larger the protected group, the fewer the number of spares required for similar improvements in yield, but also the more difficult the task of making all the controls and dataflow available to the spare(s). In the case of the Level 2 Cache chip for the planned IBM Z6 computer, there are 4 protected groups with 192 SRAM macros per group. Each protected group is supplanted with an additional 2 spare SRAM macros, along with sparing controls and dataflow that allow either spare to replace any of the 192 protected SRAM macros.

Abstract: A semiconductor integrated circuit includes: an input/output cell that is included in a path captured during propagation delay testing and that has an output-stage buffer on an output bus; and a terminal connected to the output bus and an input bus of the input/output cell. An external load or a testing device is connectable to the terminal. The input/output cell has a switching part that is capable of switching between a first path that loops back at an output side of the output-stage buffer and a second path that loops back at an input side of the output-stage buffer. The first path is selected during normal operation and the second path is selected during the propagation delay testing.

Abstract: A semiconductor integrated circuit includes a memory, a BIST main circuit and a BIST sub circuit. The BIST sub circuit is to generate a row address pattern or a column address pattern of the memory and includes a boundary address generation circuit for alternately generating a top address and a bottom address of the memory for at least one of the row address pattern and the column address pattern. The BIST main circuit is provided in common with a plurality of memories and the BIST sub circuit is individually provided corresponding to the memories. The boundary address generation circuit includes a top address memory unit for storing the top address and a top/bottom address generation unit for reading out the top address and alternately outputting the top address and the bottom address.

Abstract: A test circuit for testing a command signal at a package level in a semiconductor device includes: a logic level determining unit for determining logic levels of a plurality of command flag signals in response to a plurality of internal command signals in a test mode; a storage unit for storing the plurality of command flag signals in response to a store control signal and outputting the plurality of command flag signals in series in response to an output control signal; and an output unit for driving an output signal of the storage unit to a data pad.

Abstract: A semiconductor device that includes a module under test that is integrated with the semiconductor device, that receives an input signal from a test module, and that provides an output signal to at least one output terminal based on the input signal. An error detecting module is integrated with the semiconductor device, samples values of the output signal, and outputs the sampled values to the test module.

Abstract: An apparatus and method for a processor-memory unit for use in system-in-package (SiP) and system-in-package (SiP) integrated circuit devices. The apparatus includes a processing module, a memory module and a programmable system module. The programmable system module is configured to function as an interface between the memory module and the processing module, or as an interface between the memory module and a testing device. The invention facilitates integration and testing of processor-memory units including functional components having different communication protocols.

Abstract: According to the present invention, the outputs of the last scanning flip-flop circuits 12 included in scan chains 111 are compiled and compressed in an output compression circuit 112, a sum of the outputs from the scan chains 111 and an expected value written in an expected value storage circuit 113 from the outside are compared with each other in an expected value decision circuit 114, the sum being outputted from the output compression circuit 112, a pass/fail decision result obtained by the comparison can be outputted from an output terminal 116 of the expected value decision circuit 114 to the outside, and the decision result can be stored regardless of the reset of a system.

Abstract: The present invention provides a method and system for routing a group of scan chains to a group of processor resources in a semiconductor chip. The group of processor resources is arranged in rows or columns. The group of processor resources in each row or column is connected through a plurality of scan chains. The first processor resource in each row or column is connected to input scan-chain pins, and the last processor resource in each row or column is connected to output scan-chain pins. A test-pattern generator, generating test signals, sends the test signals to the group of processor resources by using the group of scan chains within the semiconductor chip. The responses of the processor resources corresponding to the test signals are analyzed to detect and locate any error in the manufacture of the semiconductor chip.