Abstract: An implementation of a serial access memory register facility which allows the external selection of the portion of the SAM to be scanned out. A control signal is provided which causes the reloading of serial access memory address counter causing the reloading of serial access memory address counter causing the serial scanning to shift from one to another of the serial access memory registers. The result is an ability to select a stopping point when scanning out of the serial access memory. Thus, the present invention implements the ability in a video random access memory to specify both the starting and ending points of the data to be scanned out of the serial access memory. The preferred embodiment replaces the QSF status pin with a control pin to preserve the packaging configuration of standard VRAMs.
Type:
Grant
Filed:
May 16, 1989
Date of Patent:
March 19, 1991
Assignee:
International Business Machines Corporation
Inventors:
Timothy J. Ebbers, Satish Gupta, Randall L. Henderson, Nathan R. Hiltebeitel, Robert Tamlyn, Steven W. Tomashot, Todd Williams