Abstract: As a scan pattern is shifted out of a scan chain, the scan pattern is evaluated in real-time for the existence of a logic condition. A reference to a portion of the scan pattern that is currently being evaluated is maintained. Upon identifying the existence of the logic condition when the reference has a predetermined relationship to a stored value, the stored value is overwritten using the reference. The stored value is then used to estimate the position of a stuck-at defect in the scan chain.

Abstract: A failure mask memory is added to a semiconductor tester. In conjunction with a new failure filter, failures may be ignored or used to update the contents of failure mask memory. Only the first instance of a failure is reported reducing the size of test data logs.

Abstract: An apparatus for locating a defect in a scan chain by recording the last bit position in a serial data stream at which a certain data state is observed during a test comprising a plurality of patterns.

Abstract: As a scan pattern is shifted out of a scan chain, the scan pattern is evaluated in real-time for the existence of a logic condition. A reference to a portion of the scan pattern that is currently being evaluated is maintained. Upon identifying the existence of the logic condition when the reference has a predetermined relationship to a stored value, the stored value is overwritten using the reference. The stored value is then used to estimate the position of a stuck-at defect in the scan chain.

Abstract: An attribute control system is provided in a word processing system of the type having a keyboard for entering alpha numeric data. A display control circuit is coupled between a display, which displays a plurality of lines of alpha numeric text, and the keyboard. The display control circuit controls the information exhibited on the display. The display control circuit means includes a character attribute control circuit having a latch for latching attribute signal information entered from the keyboard. The attribute signal information remains in the latch until the attribute latch is cleared or another attribute signal is entered from the keyboard.

Abstract: A data processing system embodying the present invention includes a plurality of data processing stations. Each station includes a first communications interface connected to a common communication channel and a second communications interface for communicating with one or more associated controlled units. Each station also includes a processor and a memory; the processor and the interfaces being operatively connected to the memory, so that each may access the memory, and to a contention resolving circuit for resolving memory access conflicts.

Abstract: A circuit for controlling information on a display includes two character generators. Each character generator is coupled to a row counter and a character latch which latches character information. The row counter is energized by line synchronization information. A width generator is coupled to both the character latch and a counter. Two shift registers are connected respectively to the first and second character generators and to a means for generating output signals for application to the display. The counter coupled to the width generator has its output signals applied to the character latch and to the output signal generating means for the display.

Abstract: A communications system includes a plurality of data processing stations each having a first communications means connected to a common communications channel. Each of the data processing stations also includes a second communications means adapted to be connected to one or more associated units. Each station includes a contention resolving circuit connected to a processing means, the first communications means and the second communications means. The contention resolving circuit is further coupled to and controls access to a memory for the data processing station. Controlled units such as mass storage data entry and retrieval means and a keyboard for entering alpha numeric data information, each having a controlled unit communications means are provided. These units are connected by their associated communications means to the second communications means of respective ones of the plurality of data processing stations.