摘要:
A semiconductor memory device includes a self-testing circuit and a self-redundancy circuit with simple structures. The self-testing circuit includes a comparison circuit which compares write data with read data with respect to normal memory blocks and redundant memory blocks, and a decision circuit which decides if the semiconductor memory device is good or defective based on the plurality of comparison result signals. A signal transfer and holding circuit is connected between the comparison circuit and the decision circuit to transfer the plurality of comparison result signals to the decision circuit and to supply the plurality of comparison result signals to the self-redundancy circuit as a test result.
摘要:
When a special operation mode is instructed, a test oscillation circuit operating at a cycle shorter than a refresh oscillation circuit specifying the cycle of self refresh is activated according to an external row address strobe signal. The internal row address strobe signal is provided to row related control circuitry via a selector. An internal row address strobe signal can be rendered active at a cycle shorter than the cycle of the external row address strobe signal, to carry out row selection. A row is selected at a cycle shorter than the transition cycle of an external signal.
摘要:
The semiconductor memory device has a word configuration determination signal generating circuit including a plurality of generating circuits, each of which is formed of two clocked inverters and two inverters. In a normal operation mode, a test mode signal TX4 is inactivated and a word configuration determination signal [x16E] of an H level is output. In a test mode, the test mode signal TX4 is activated and a word configuration determination signal [x4E] of an H level is output. Thus, in the test mode, the word configuration is switched to the one that is smaller than in the normal operation mode. This allows simultaneous testing of a larger number of semiconductor memory devices.
摘要:
A probe card is used to test an electronic device. The probe card includes a base plate and a cantilever-type probe arranged on the base plate. The cantilever-type probe has an end that contacts the contacted body and moves when contacting the contacted body. A stopper arranged on the base plate restricts the movement of the cantilever-type probe.
摘要:
An electromagnetic relay is provided with an iron core (50) which has a virtually J-letter shape on a plan view with one end serving as a support-receiving portion (51) and the other end serving as a magnetic pole portion (52), and a movable iron member (60) which is supported by a movable contact member (70) attached to a corner thereof, and has a virtually L-letter shape on a plan view with one end (61) being supported on the support-receiving portion (51) of the iron core (50) so as to freely pivot thereon and an adsorb portion (62) that is the other end being allowed to face the magnetic pole portion (52) of the iron core (50) so as to be adsorbed thereon. The objective of the present invention is to provide an inexpensive electromagnetic relay which is less susceptible to deviations in the adsorb portion of the movable iron member that comes into contact with and separates from the magnetic pole portion of the iron core, and has stable operation characteristics.
摘要:
An optical fiber holding member in which occurrence of defectives is prevented by increasing the degree of accuracy in pitches of the optical fibers with a simplified manufacturing method, and a method of manufacturing the same are provided. A deflection generating block is disposed in a cavity for molding a holder, and a positioning block is disposed in contact with the cavity. The deflection generating block is formed with V-shaped holding grooves for the optical fibers. The positioning block has grooves for placing the optical fibers. The holding grooves and the grooves are shifted laterally of the extending direction of the optical fibers. The optical fibers and the positioning surfaces of the grooves are in press-contact by a resilient restoring force of the optical fibers, and are positioned in the lateral or vertical direction. In this state, resin is injected into the cavity, whereby obtaining the optical fiber holding member.