Resources Contact Us Home
Hardware portrait mode support

Image Number 5 for United States Patent #6639603.

A display subsystem supports both normal mode and portrait mode displays. In normal mode, the scan starts at the upper left comer of the display. In portrait mode, the scan starts at the lower left comer of the display. The display subsystem includes a dual mapped display memory having a normal mode display area and a portrait mode display area. The portrait mode display area is defined by X-ofst.sub.(Virtual) and Y-ofst. X-ofst.sub.(Virtual) is a power of two that is greater than the real X-ofst supported by the display in portrait mode. Address requests from the CPU or software use high order bits to specify whether the address is in the normal or portrait mode display area. In addition, address requests to the portrait mode display area use the address space defined by X-ofst.sub.(Virtual) and Y-ofst. When the address request specifies the portrait mode display area, the address of the request is translated to account for the different mode of the display. Since X-ofst.sub.(Virtual) is a power of two, the X-coordinate of the display location specified by the address can be determined without a division operation, thereby allowing for fast address translation. Logic within the display subsystem rapidly translates the address and supports a range of Y-ofst values.

  Recently Added Patents
Switching element for a valve train of an internal combustion engine
Case for electronic device
Spoofing detection for civilian GNSS signals
Generating and using checkpoints in a virtual computer system
Dual source mass spectrometry system
Reconfigurable barrel shifter and rotator
Materials for organic electroluminescent devices containing substituted 10-benzo[c]phenanthrenes
  Randomly Featured Patents
Image data communications device and method
Integrated memory having column decoder for addressing corresponding bit line
Insulated water-tight connector assembly including a set screw driver and plug
Soybean variety D5632454
Method of fabricating a phase shift mask
Piezoelectric vibrator
Method and device for machine-cutting a plate-shaped workpiece
Method and buffer device for data stream transformation
Method of producing propeller shafts for jet-propelled small-sized boats
Positioning mechanism for locating the edge of an ink metering means