Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Semiconductor Software Co., Ltd

Takahiro Ohtsuka

Nobusuke Abe

Yoshikazu Satoh

Shozo Shirota

An output timer includes a capture register for capturing a count value held by a free running up-counter in coorporation with a transmission gate in response to an event signal applied to the output timer. An adder adds a first value stored in another register to the count value captured by the capture register and produces a sum. A comparator compares a count value held by the free running up-counter with the sum and outputs a coincidence signal when the count value and sum are equal to each other. A set-reset flip-flop includes a set terminal for receiving the event signal and a reset terminal connected to the output terminal of the comparator.

Output timer

A semiconductor memory apparatus capable of judging whether or not there is short circuit between bit lines 1 (word lines) by respectively connecting a plurality of the bit lines 1 (word lines), wired in parallel to each other so as to select memory cell for outputting data from a memory cell array 4 in which memory cells are arranged in the form of matrix, connected to power source potential line 14 and ground potential line 16 alternately through switching elements 5, 6 respectively, thereby measuring leak current flowing between the both lines 14 and 16 in the state where the switching elements 5, 6 are ON, a testing apparatus being provided with a power source 10 supplying to each of the switching elements 5, 6 of this semiconductor memory apparatus and with an ampere meter 11 for measuring leak current, and relieving method for the semiconductor memory apparatus from short circuit between the bit lines (word lines) by making the switching elements 5, 6 ON as well as applying overvoltage to the bit lines (word lines) from the power source 10, thereby generating Joule heat at foreign matter which short-circuits between adjacent bit lines 1 (word lines) so as to burn off the foreign matter by the Joule heat.

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Tokyo, Japan

Takahiro Ohtsuka