摘要:
A video controller receives character data, attribute data and font data, each of which are stored in different planes of a video memory. The font data comprises bit maps of at least two character fonts, which may be user fonts or default fonts loaded from a controller BIOS. The video controller retrieves the font data, translates the font data into a page mode, and stores the font data in a hidden font cache in an unused portion of the video memory. The paged font data is divided into a number of pages equal to the number of scan lines per character. Each page contains a number of words, and each word contains at least two bytes. Each byte represents one scan line of a character in a different font. The video controller retrieves the paged fonts in page mode and assembles the scan lines for the characters to be displayed into one video scan line. The use of the page mode increases refresh rate and allows simultaneous display of two fonts.
摘要:
A computer video controller, particularly a VGA or SVGA video controller for use with graphical user interface (GUI) software such as WINDOWS.TM. or OS/2.TM. is provided with two video data pipelines for simultaneously displaying full motion video within a window in a video display. A first data pipeline displays background video at a first pixel depth. A second data pipeline is provided to display a motion video window at a second, usually higher, pixel depth. The location of the motion video window is measured horizontally in number of memory fetch cycles needed to retrieve the horizontal scan line of pixel data abutting the motion video window. The width of the motion video window is measured in the number of memory fetches required to retrieve one scan line of the motion video window. By providing two parallel data pipelines having equal delays, the motion video window can be generated by selectively retrieving background pixel data or motion video window pixel data and transferring the data to the appropriate pipeline. In an alternative embodiment, data tags may be used to distinguished between background and motion video window pixel data. The controller may also support various compression formats for motion video.
摘要:
A flat panel display controller is provided with a circuit for monitoring clocking signal(s) to the flat panel display. A clocking signal output to the flat panel display may be fed back to the display controller using a conventional I/O pad. In the preferred embodiment, the fed back clocking signal resets a counter. In a second embodiment, the fed back clocking signal may then pass through an edge detector whose output then resets the counter. The counter will overflow if a edge signal is not received within a predetermined time period. If an overflow occurs, the carry signal of the counter will initiate a flat panel power shutdown through power control circuitry. The clock signal for the counter may be derived from an off-chip oscillator such that if a failure occurs within the display controller, the counter will continue to function.
摘要:
A television system (TV) with an interlaced display screen for displaying network application data. A flicker filter is preferably implemented as an infinite impulse response (IIR) filter to eliminate sharp transitions in the network application data images. A random access memory is used to store the lines of the filtered images and any adjacent lines used for the filtering operation. Alternate lines of the filtered images are retrieved from the random access memory to provide an interlaced image of the filtered network application data images. The interlaced images are displayed on an interlaced display unit of a television system.
摘要:
A display controller in a computer system controls the output of graphics display data in a computer system having a fixed resolution flat panel display. Fixed panel displays may have problems displaying non-native resolutions particularly at lower resolutions. The controller of the present invention uses a Discrete Time Oscillator (DTO) based clock divider and DCT based polyphase interpolation to upscale graphics display data from a first resolution to the panel resolution. DTO clock divider circuit synchronizes scan clocks between the input resolution and the desired output resolution. Within graphics display area, MVA.TM. display at greater color depth and resolution may be accommodated by additional DTO divider and interpolation steps.
摘要:
A video controller for controlling at least two video displays having independent refresh rates and pixel resolutions. In a first embodiment, two separate data paths are provided within a video controller for each video display (e.g., CRT and LCD). Taking advantage of the increased bandwidth of 64 bit wide DRAMS, data for each data path may be retrieved in separate read cycles. Each datapath may operate at its own clock frequency characteristic of refresh rate and pixel resolution. The dual data path embodiment also reduces the complexity of the software model needed to drive such dual displays. IN an alternative embodiment, a single data path may be provided within a video controller to drive data for two video displays having independent refresh rates and pixel resolutions. A data "tag" (extra bit) is attached to each word or dword passing through the data path indicating the destination (e.g., CRT or LCD) of the video data. At the output of the data path, separate FIFOs (e.g., LCD and CRT) are provided to temporarily store video data. FIFO pointers are fed back to a sequence controller to drive data read cycles from display memory. The use of tags and FIFO pointer feedback allows two video displays to be driven at different data rates, allowing for independent resolution and refresh rates in each display.
摘要:
A television system (TV) which enables a user to view display represented by a television signal as well as to access data network applications. The TV includes an on-screen-display (OSD) controller which stores the network application data and other display entities in a memory module as separate bit maps. A single image for display on a TV display screen is generated by overlaying all the display entities (including television signal, network application data, pointer, and low resolution data) according to a predetermined priority. Display entities (other than TV signal) are stored in separate portions of the memory module as independent surfaces to enable the displays of individual display entities to be generated and modified according to the individual display entity requirements.
摘要:
A method and apparatus for compensating crosstalk in liquid crystal displays is disclosed which involves applying boost voltages to the rows and columns of the display in proportion to the number of ON pixels in a row or column, the number of transition between "ON-and-OFF" or "OFF-and-ON" in each column, and the position of the pixel in a row. "Boost" voltages are applied to each row as it is being actively scanned to provide horizontal crosstalk compensation, while "boost" voltages are applied to each column during the vertical retrace interval of the display sequence to provide vertical crosstalk compensation. In a preferred embodiment, the vertical crosstalk compensation is determined during the vertical retrace interval over several flames.
摘要:
Modifications to a prior art system known as video graphics adapter (VGA) for displaying color images on a monitor attached to a personal computer. The modifications provide the following four enhancements to a standard VGA system: (i) user definable border color; (ii) automatic powering down of the digital analog converter (DAC) component of the VGA RAMDAC and monitor sense comparator for LCD monitors when the RAMDAC is not in use; (iii) stopping of the RAMDAC clock for LCD monitors when the RAMDAC is not in use; and (iv) true color support.
摘要:
This invention describes the design and implementation of a low power CMOS bidirectional I/O buffer that translates low voltage core logic level signals into the highest logic level signals to drive the final output stage which outputs a selectable logic level signal. The invention further translates input signals of a variety of logic levels into low voltage core logic level signals. In either case, AC and DC power consumption is minimized in a mixed power supply environment that requires voltage translation to represent the proper binary logic levels.