74 results about "Bit Test" patented technology

A set of memory cell test structures and a method are disclosed for assessment of the static noise margin (SNM) of a memory cell or an array of such cells, for example, of SRAM cells of an integrated circuit device, using discrete point measurement structures provided either on-chip or within the scribe lines. In one embodiment, the set of memory structures comprises first and second test structures, individually comprising a memory cell, having one or more left and right half-bit test structures having hard-wired connections between select nodes of each memory cell half-bit and one or more voltage supplies. The half-bits of the first test structure are configured for measuring respective left and right standby SNM values, and the half-bits of the second test structure are configured for measuring respective left and right cell ratio values at respective output nodes of the structures, using applied supply voltages for on-chip assessment of the static noise margin of the memory cells. The method applies the supply voltages to select nodes of the test structures, measures left and right standby SNM values at a first test structure, measures left and right cell ratio values at a second test structure, determines a first difference between the left half-bit standby SNM value and the right half-bit cell ratio value, determines a second difference between the right half-bit standby SNM value and the left half-bit cell ratio value, and determines a smaller one of the first and second difference values proportional to an SNM value of the cell.

The invention discloses a 10 Gbps bit error analyzing instrument and aims to provide a bit error analyzing instrument which has low cost, simple and convenient operation and convenient carrying and issuitable for engineering field test. The 10 Gbps bit error analyzing instrument comprises an evaluation board and a single chip microcomputer of C8051 series, wherein the evaluation board can carry out communication with a PC, and a bit error test chip which is connected with equipment to be tested is arranged on the evaluation board; and the single chip microcomputer is used for carrying out communication with an upper PC and a lower test chip, and is provided with a USB interface which carries out communication with the PC and an I2C double line type serial bus which is connected with the bit error test chip to carry out communication and control. The bit error test chip provides sent bit flow and total amount of bit error to the PC through the single chip microcomputer, and the sent bit flow is obtained by test time recorded by the single chip microcomputer and appointed frequency output by the test chip. The invention has the advantages of convenience, rapidness and accurate bit error analysis test and is suitable for performance test of a 10 Gbps communication system.

The invention relates to a slave machine address test method for a master-slave type serial communication in the technical field of electronic communication. The method is as follows: In accordance with a pre-defined coding rule between a host computer and slave machines, the host computer sends the first scanning command to zero registers in the slave machines; the host computer sends address bit test signal according to the binary bit length of the slave machine address; the slave machines follow the address binary bit value to perform current feedback for the signal, and determine whether perform continuous feed according to the variation; the host computer can identify the address of the first slave machine; then, the second scanning command is launched, and the rest slave machines zero registers respectively before repeating the actions in the previous execution step; the host computer can identify the address of the second slave machine, and identically, test address of the rest slave machines, until the detected addresses of the slave machines are all 1. The invention can simplify communication links and interface circuits, increase communication convenience and efficiency of host computers and slave machines, and increase test possibility of network interconnection. Therefore, the invention can lower comprehensive cost of relevant products, and have rather high value in actual application.

A circuit for testing a semiconductor memory device includes a data comparator and a signal aligner. The data comparator compares a first output data and a second output data provided from an output buffer circuit. The data comparator determines whether logical states of the first output data and the second output data are identical to generate a comparison signal. The signal aligner aligns the first output data and the comparison signal, and generates a plurality of test signals in response to a clock signal. The test signals includes an even bit test data, an odd bit test data, an even bit comparison test data and an odd bit comparison test data. The even bit data and the odd bit data are simultaneously tested by using one pattern, and a correct test result is yielded even when test data are all inverted.

Example embodiments are directed to a parallel bit test device and method using error correcting code. The parallel bit test device may include an error detecting and correcting unit configured to count the number of fail bits in an m-bit data signal, for example, by comparing bits of the m-bit data signal with corresponding bits of expected data, where m is a positive integer, and to output correction signals. The error detecting and correcting unit may be further configured to perform at least one logic operation on a correction control signal and comparison signals. The correction control signal may be generated in response to a test mode register set (TMRS) signal set and input by a user such that the logic level of the correction control signal may vary according to the counted number of fail bits. Each comparison signal may include information about a fail bit and the address of the fail bit.

Internal read out data bits are divided into a plurality of data groups, and data bits in corresponding positions in different data groups are paired off. A determination gate is provided to each pair of data bits, and determining operation is performed in each pair to compress the result of determination to finally generate a 1-bit flag indicating a match/mismatch in logic level among the internal read out data. Consequently, a multi-bit test circuit that has a reduced layout area and can perform high-speed multi-bit determination is provided.

A memory device includes a memory cell array to store data, a register to store test data, and a decision circuit to invert the test data and to determine a failure of at least one memory cell within the memory cell array responsive to the data, the test data, and the inverted test data.

A method for testing a memory cell array of a semiconductor memory device in a parallel bit test mode includes selecting first data from one of a plurality of memory regions in the memory array for output from the memory device via an input/output pad, and then selecting second data from another of the plurality of memory regions for output via the input/output pad. The first and second data can be selected from memory regions sharing a row select or a column select control line. Alternatively, one of the first and second data can be selected from memory regions sharing a row select control line, and the other can be selected from memory regions sharing a column select control line. Therefore, a parallel bit test can be performed using fewer input/output pads, and a larger number of semiconductor memory devices can simultaneously be tested. Related circuits are also discussed.

An automatic double-probe test platform based on a bitmap tracking method mainly comprises a base, a carrying table, a first probe support, a second probe support, a main control computer, a first driving mechanism and a camera, wherein the first driving mechanism drives the carrying table to rotate in the horizontal plane and to be lifted up, the camera is arranged above the carrying table, the shooting direction of the camera faces downwards, the carrying table can rotate, be lifted up and move in the Y-axis direction, and the first probe support and the second probe support can carry out horizontal movements and horizontal mirror symmetry movements in the same direction. According to the automatic double-probe test platform based on the bitmap tracking method, the automatic locating of double probes is achieved through a bitmap control technology, the automated locating tests of two testing points of a sample is achieved accordingly, the labor intensity of testing personnel is reduced greatly, and the testing accuracy is improved. The automatic double-probe test platform based on the bitmap tracking method is novel in locating mode, the rotating movable type carrying table and the movable symmetrical open type double probe supports are utilized ingeniously, the probes can be located at any two testing points of the sample to be tested, and the automatic double-probe test platform can meet testing demands.

The invention discloses a test system of full gauge drilling bit rock breaking. The test system of the full gauge drilling bit rock breaking is mainly formed by a drilling bit test rack (1), a lower turnplate (2), a measuring connector (3) and a displacement sensor (4), wherein the lower turnplate (2) is arranged below the drilling bit test rack (1), the measuring connector (3) is installed on the drilling bit test rack (1), the drilling bit test rack (1) is connected with a driving device, and the measuring connector (3) and the displacement sensor (4) are both connected with an identical measuring and control device. The rate of penetration and the broken shaft bottom of different rock breaking of the drilling bit under a certain parameter condition are mainly detected, and characteristics of the rock breaking with the drilling bit can be reflected simply and really.

The invention is a method and system for realizing mono-chip working position testing, and the method includes the steps: starting up a testing background system and selecting the required testing items; communicating a foreground mono-chip with the background system, where the foreground mono-chip is normally power-on and enters in a testing mode; the background system starts up testing and sends the information corresponding to the testing items to the foreground mono-chip in turn; the foreground mono-chip receives the information to resolve it and makes a testing processing flow on it and after primary testing is completed, returns tested result in a fixed information returning form to the background system; the background system receives the tested result and then makes the corresponding resolution according to different testing items and displays the tested result in the interface of the background system. The invention raises the speed of a MCU processing other functions.

Provided is a test system conducting a parallel bit test. The test system, conducting a parallel bit test on a plurality of memory modules mounted on a socket, comprises a plurality of counters and a comparator. Each of the counters counts the number of data output signals in the same logic state, among the data output signals outputted from each memory of the memory modules, and outputs a count signal. The comparator compares the count signal outputted from each of the counters and outputs a comparison signal corresponding to a defect of the memory modules. According to the test system, defects in a memory module can be accurately detected and a possibility of an error in the detection can be reduced when a plurality of memory modules are tested, as compared to conventional test systems.

A parallel bit test (PBT) apparatus, included in memory chips that are stacked in a multi-chip package (MCP) and that share a set of data signal lines, may include: a comparing unit to output a data signal representative of a comparison between test data signals provided to a given one of the memory chips and corresponding data signals output therefrom, respectively; and a coding unit to output the representative data signal using a first subset of the shared set of data signal lines, the first subset not overlapping other subsets used by coding units corresponding to the other ones of the memory chips, respectively, the coding unit selecting one or more of the data signal lines amongst the shared set of data signal lines for inclusion in the first subset according to a first test mode register set (MRS) signal.

The invention belongs to the field of FPGAs (Field Programmable Gate Array), and particularly relates to a partial bit stream read-back technology for testing internal resources of an FPGA (Field Programmable Gate Array), which can improve the defects of an existing FPGA internal resource testing method. The method comprises the following steps: firstly, resetting a test access interface controller, setting a read-back starting frame address, and starting bit stream read-back operation from the address; and then setting the length of the read-back data to be used for stipulating the total number of frames read from the start frame address to the completion of the read-back, and then setting the FPGA to be in a read-back state; after the setting is completed, enabling the last step to start reading data from the FPGA configuration register chain and store the data, so that the data can be used by an FPGA test platform based on a partial bit stream read-back technology. A partial bit stream read-back technology is adopted, so that the high efficiency of FPGA internal resource testing is ensured, the universality is higher, and the method can be transplanted to different series of FPGAs to be used for testing the FPGA internal resources.

A semiconductor memory device performs a parallel bit test on a plurality of memory blocks by writing test pattern data into the plurality of memory blocks, outputting two bits from each memory block in parallel and comparing the two bits output from each memory block with each other in a first test mode, and outputting two bits from respectively different memory blocks and comparing the two bits output from the respectively different memory blocks with each other in a second test mode.

The present invention provides systems, devices and methods for generating user-defined test patterns within serial controller to facilitate signal testing and verification. These user-defined test patterns may be generated to more accurately reflect the actual traffic of a device-under-test or system, as well as allow a test engineer to more accurately test the boundaries of the device or system. In various embodiments of the invention, a programmable patterns generator is provided for generating user-defined test patterns that may be used during a testing procedure. This programmable pattern generator allows a user to define a particular test pattern by providing bit-by-bit test values, by defining a combination of canned sequences, or by supplementing one or more canned sequences with additional test bits.