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
Polymer composites having highly dispersed carbon nanotubes
Display device and method of manufacturing the same
Wind farm, wind power plant in a wind farm and operating control for this purpose
Polarized film apparatus with bands of alternating orientation
Information display device and program storing medium
Method and apparatus for transcoding and transrating in distributed video systems
Active and progressive targeted advertising
  Randomly Featured Patents
Fabric for non-woven web forming process and method of using same
Highly damped storage rack for nuclear fuel assemblies
Process for upgrading solids-containing liquid hydrocarbon oils
Implosion protection for TV tubes
Compressor impeller and method of manufacture
Amorphous magnetic alloy
Memory circuit with improved serial access circuit arrangement
Disturb-resistant non-volatile memory device and method
Method and apparatus of certifying a telephonic transmission