Testable video display generator

Abstract

Abstract A display generation system comprises a memory 22 with a display portion storing display information, and an inactive portion storing test data. Scan logic 20 controls a monitor and accesses the memory at locations corresponding to the position of a scan beam of the monitor. A generator 16, 26, 28, 30, 32 generates display control information to provide information control signals to the scan beam, so displaying the information stored in the display portion of the memory. A register 34, 36 stores display control information generated from the test data stored in the inactive portion of the memory, the register being enabled by a control signal generated from the scan logic indicating the end of a display frame. The scan logic is operative during a period of time that the monitor is blanked to allow the scan beam of the monitor to be positioned to a beginning point of the display. An element 10 compares the display control information stored in the register corresponding to the test data with an expected result, the comparison being performed during the period of time the monitor is blanked, thereby verifying on-line that the display generation system is functioning correctly.

Inventors

• 👤 Kevin P. Staggs

Bibliographic Details