| 摘要 |
A method of providing a zoom feature for a handheld computer is described. The method uses a combination of software and hardware to provide the display zoom without using significant processor resources, or adding dedicated zooming hardware to the display. The method includes storing the image for the display in a memory and using the processor and the memory controller to store the image so that when it is retrieved by the display controller, for transfer to the display circuit, it is already zoomed in a fist direction. The method also includes using a pixel replication circuit to provide the replication of pixels in the other direction. The pixel replication cicuit takes a row of pixels and doubles each pixel in the row. This combination allows for the consumption of relatively little processing resources and does not require extensive additional hardware. In some embodiments, the operating system software and other software that writes to the display memory is modified so that write operations occur multiple times to provide the zoom effect. In other embodiments, the display software is modified to leave empty rows in the display memory. A memory access controller can map a request by the display controller for pixel data from an empty row onto the corresponding row with pixel data. |
