Computer system including protected graphics display control signal sequencing

A graphics control system for an information handling apparatus which includes a processor and a main memory coupled to the processor, the information handling apparatus further including a display, the graphics control system comprising:

• a graphics controller for supplying clock signals, data signals and an enable signal;
• a switching apparatus switchably coupling the graphics controller to the display;
• and
• a microcontroller coupled to the graphics controller, the switching apparatus and to the display, the microcontroller monitoring for a first transition in the enable signal, the microcontroller generating a first sequence of display control signals to power-up the display when the microcontroller detects the first transition in the enable signal, the microcontroller activating the switching apparatus to a coupling state to permit transmission of the clock signals and data signals from the graphics controller to the display after the microcontroller detects the first transition in the enable signal.

An information handling system comprising:

• a processor;
• a local bus coupled to the processor;
• a main memory coupled to the processor;
• a graphics controller coupled to the local bus, the graphics controller supplying clock signals, data signals and an enable signal;
• a display;
• a switching apparatus switchably coupling the display to the graphics controller;
• and
• control means, coupled to the graphics controller, the switching apparatus and to the display, the control means monitoring for a first transition in the enable signal, the control means generating a first sequence of display control signals to power-up the display when the control means detects the first transition in the enable signal, the control means activating the switching apparatus to a coupling state to permit transmission of the clock signals and data signals from the graphics controller to the display after the control means detects the first transition in the enable signal.

A method of controlling a display system for an information handling apparatus, the display system including a graphics controller coupled by a switching apparatus to a display, the display system further including a microcontroller coupled to the graphics controller, the switching apparatus and the display, the method comprising the steps of:

• the graphics controller generating clock signals, data signals and an enable signal;
• monitoring, by the microcontroller, for a first transition in the enable signal;
• generating, by the microcontroller, a first sequence of display control signals to power-up the display when the microcontroller detects the first transition of the enable signal;
• and
• activating, by the microcontroller, the switching apparatus to a coupling state to permit transmission of the clock signals and data signals from the graphics controller to the display after the microcontroller detects the first transition of the enable signal.