Nippon Telegraph and Telephone Public Corporation

Takeda Riken Kogyo Kabushiki Kaisha

Takeca Riken Kogyo Kabushiki Kaisha

Hiromi Maruyama

Masao Shimizu

Tsuneta Sudo

Yoshichika Ichimiya

Shigeru Sugamori

Takashi Tokuno

Susumu Sumida

Kohji Ishikawa

Naoaki Narumi

Osamu Ohguchi

Toshiaki Wakita

Input logical data is sequentially divided by a data dividing circuit for each time slot into n data trains, of which each data block has an n time slot length. A clock signal which can be arbitrarily timed, is divided by a clock dividing circuit into a n clock signals which are displaced one time slot apart in phase and which occur with a period of n time slots. In a logical circuit, the divided clock signals are controlled by the divided data trains corresponding thereto, and the controlled clock signals are time multiplexed by a multiplexing circuit, whereby output data with which the input logical data has been timed by the clock signal is obtained.

Logical waveform generator

An address pattern generator for use in a test pattern generator for generating various patterns for testing semiconductor memories. A plurality of fixed registers for storing an initial value at the start of a test, a boundary value and an operand indicating the amount of change of an address are provided in common to at least two address operating circuits. The address operating circuits are each capable of taking therein the content of a desired one of the fixed registers. At least two output registers are provided, which are each capable of taking therein the operation result of a desired one of the address operating circuit. The contents of these output registers are supplied as addresses to a memory under test.

Address pattern generator for testing a memory

Reference logical data is spatially divided by a data dividing circuit for each time slot, and the divided data are converted into data, each having a continuous effective period. The divided and converted reference data and input logical data are compared by comparators to detect whether or not they are coincident with each other. A clock signal for determining the timing of comparison is also divided by a clock signal dividing circuit into n clock signals which are displaced one time slot apart in phase and occurring with a period of n time slots. By these divided clock signals those of the outputs from the comparators corresponding thereto are taken out from a comparison output circuit.

High speed data logical comparison device

Growing community of inventors

Gyoda, Japan

Hiromi Maruyama