A semiconductor device, for use in a semiconductor memory device, for controlling a core voltage generator for providing a core voltage to be coupled to a bit line sensing amplifier, comprises a bit line sensing start signal controller for receiving a bit line sensing start signal to generate a delayed bit line sensing start control signal in response to a refresh signal; a core overdriving controller for generating an overdriving control signal in response to the delayed bit line sensing start signal; and a core voltage generator for generating the core voltage in response to the delayed bit line sensing start signal and the overdriving control signal to thereby provide core voltage to the bit line sensing amplifier after a predetermined delayed time from the bit line sensing start control signal.

A presentation device includes an embedded web server for transmitting images representative of presentation information to network-connected terminals concurrently with the display of such presentation information at the presentation site. The images may be viewed at the terminals by pointing a conventional web browser to a DNS name or IP address associated with the presentation device. Certain of the terminals may be given presenter privileges, wherein the users of the presenter terminals may control aspects of the presentation such as slide sequencing by engaging the appropriate controls displayed within the browser window. In this manner, presentations may be viewed and controlled remotely using a conventional browser interface.

Geographically distributed conference sites each have a telephone receiver and a dataconferencing appliance connected to a shared voice call network. Each site also has a display device for displaying images comprised of image data produced by an image source. The dataconferencing appliance is connected to a data network that links the sites independently of the voice call network. To initiate a dataconference session between the sites, a voice call session is first established between the telephone receivers via the voice call network. An address negotiation procedure implemented in software or hardware of the dataconferencing appliance is then manually initiated to identify a network access code and communicate it to at least a second one of the sites within the voice call session. The network access code is used to establish a data communication session via the data network for convenient transmission of image data between the sites.

Preferred data compression and decompression processes (500, 600) of this invention speed transmission of a color XGA image (502). A first compression step employs an RGB-to-YCrCb color conversion compression process (504), and a second step employs an Lempel-Ziv-Oberhumer ("LZO") compression process (506) for generating compressed image data for transmission through a wireless transmission medium. A preferred data decompression process receives the compressed image data from the LZO compression process. A first decompression step employs an LZO decompression process (602), and a second decompression step employs a YCrCb-to-RGB color conversion decompression process (604) for generating decompressed data suitable for rendering an image (606) that is substantially the same as the original XGA image.

A method and an apparatus for controlling a conference call is a system which comprises a conference bridge for combining several audio signals arriving from terminals and for transmitting the combined signal further to at least one of the terminals using at least one transmitting codec. The conference bridge comprises a spatialization unit for creating a spatial effect. The number of simultaneously active audio components, such as speech signals, is determined from the audio signals of the conference bridge inputs. At least one transmitting codec is selected for use on the basis of the number of simultaneously active audio components and the combined signal is transmitted to at least one terminal using the selected transmitting codec.