Communication apparatus and method for transferring image data from a source to one or more receivers

A method for transmitting image data over a communication bus from a source of image data to one or more of a plurality of image data receivers that are serially coupled along the communication bus, comprising the steps of:

• generating, with each of the one or more of the plurality of image data receivers, an internal Ready signal;
• storing the internal Ready signal within the image data receiver that generates the internal Ready signal;
• and
• determining with each of the one or more of the plurality of image data receivers if a downstream image data receiver, if there be one, has generated an external Ready signal indicating that the downstream image data receiver is ready to receive data;
• wherein
• if there is no downstream image data receiver for a particular one of the image data receivers, generating the external Ready signal with the particular one of the image data receivers and providing the generated external Ready signal to an upstream image data receiver, if there be one, or if not, providing the generated external Ready signal to the source;
• if the downstream image data receiver for the particular one of the image data receivers has not generated the external Ready signal, idling the particular one of the image data receivers until the downstream image data receiver generates the external Ready signal;
• if the downstream image data receiver has generated the external Ready signal, generating the external Ready signal with the particular one of the image data receivers and providing the generated external Ready signal to the upstream image data receiver, if there be one, or if not, providing the generated external Ready signal to the source;
• and in response to the reception of another received external Ready signal by the source of image data,
• transmitting image data to the communication bus, the image data being transmitted as a burst comprised of a plurality of data words, each of the data words specifying characteristics of at least one image pixel.

A method for transmitting image data over a communication bus from a source of image data to one or more of a plurality of image data receivers that are serially coupled along the communication bus, comprising the steps of:

• generating, with each of the one or more of the plurality of image data receivers, an internal Ready signal;
• storing the internal Ready signal within the image data receiver that generates the internal Ready signal;
• and
• determining with each of the one or more of the plurality of image data receivers if a downstream image data receiver, if there be one, has generated an external Ready signal indicating that the downstream image data receiver is ready to receive data;
• wherein
• if there is no downstream image data receiver for a particular one of the image data receivers, generating the external Ready signal with the particular one of the image data receivers and providing the generated external Ready signal to an upstream image data receiver, if there be one, or if not, providing the generated external Ready signal to the source;
• if the downstream image data receiver for the particular one of the image data receivers has not generated the external Ready signal, idling the particular one of the image data receivers until the downstream image data receiver generates the external Ready signal;
• if the downstream image data receiver has generated the external Ready signal, generating the external Ready signal with the particular one of the image data receivers and providing the generated external Ready signal to the upstream image data receiver, if there be one, or if not, providing the generated external Ready signal to the source;
• with the source of image data;
• receiving the external Ready signal and, responsive thereto, transmitting information to the communication bus for addressing one or more of the image data receivers;
• and
• with each of the addressed image data receivers,
• receiving the transmitted information from the communications bus;
• wherein the step of transmitting information transmits a plurality of data words that specify a size of and a location of a display image window.

A method for transmitting image data over a communication bus from a source of image data to one or more of a plurality of image data receivers that are serially coupled along the communication bus, the image data being transmitted in from one to N blocks, comprising the steps of:

• generating, with each of the one or more of the plurality of the image data receivers, from one to at least N internal Ready signals, the number of generated internal Ready signals being a function of a number of the blocks that the image data receiver is capable of buffering;
• storing the generated one to at least N internal Ready signals within the image data receiver that generates the one to at least N internal Read signals;
• and
• determining, with each of the one or more of the plurality of image data receivers, if a downstream image data receiver, if there be one, has generated at least one external Ready signal indicating that the downstream image data receiver is ready to receive data;
• wherein
• if there is no downstream image data receiver for a particular one of the image data receivers, generating an external Ready signal for each one of the stored internal Ready signals and providing the generated external Ready signal or signals to an upstream image data receiver, if there be one, or if not, providing the generated external Ready signal or signals to the source;
• if the downstream image data receiver for the particular one of the image data receivers has not generated at least one external Ready signal, idling the particular one of the image data receivers until the downstream image data receiver generates at least one external Ready signal;
• if the downstream image data receiver has generated at least one external Ready signal, receiving and storing, with the particular one of the image data receivers, the at least one external Ready signal that is generated by the downstream image data receiver, generating an external Ready signal for each stored internal Ready signal having a corresponding stored external Ready signal, and providing the at least one generated External Ready signal to the upstream image data receiver, if there be one, or if not, providing the at least one generated external Ready signal to the source.

An image data receiver, comprising:

• means for interfacing the image data receiver to a communications bus means that couples the image data receiver to a source of image data and to at least one other image data receiver, the source sourcing the image data in a downstream direction to the image data receiver as a packet including up to N data blocks, said interfacing means including an input port capable of receiving the signals from a downstream image data receiver and an output port capable of providing signals to the input port of an upstream image data receiver;
• means for generating and storing an indication of a capability to receive up to N data blocks from the source;
• means, coupled to said input port, for receiving and storing a signal indicating a capability of a downstream image data receiver to receive up to N data blocks from the source;
• and
• means, coupled to said output port and responsive to a presence of a generated and stored indication of a capability to receive at least one data block from the source means and also to a received and stored indication from the downstream image data receiver, for transmitting in an upstream direction towards the source a signal indicating a capability to receive up to Y data blocks from the source, wherein Y is equal to the lesser of the generated and stored indication or the received and stored indication, and wherein Y=N when the generated and stored indication and the received and stored indication both equal N.

A method of transmitting image data over a communication bus from a source of image data to a plurality of image data receivers that are serially coupled along the communication bus, comprising the steps of:

• asserting on the communication bus a Packet signal;
• transmitting a first Burst of data words, the first Burst including an image data header specifying one or more of the image data receivers;
• transmitting at least one further Burst of data words, the at least one further Burst being comprised of a plurality of data words, each of the data words specifying characteristics of at least one image pixel;
• and
• receiving the at least one further Burst with the one or more specified image data receivers.

A system for displaying image data with a plurality of display means, comprising:

• means for sourcing image data;
• a plurality of image data receiver means;
• and
• communication bus means coupling together the sourcing means and the plurality of receiver means for transferring image data from the sourcing means in a downstream direction to one or more of the plurality of receiver means, individual ones of the receiver means being coupled to the communication bus means and having a receiver port for receiving signals from the communication bus means and an output port for providing the signals to the receiver port of a next receiver means;
• wherein
• each of the receiver means includes:
• means for generating an indication of a capability to receive data from the sourcing means;
• means for receiving a signal indicating a capability of a downstream receiver means to receive data from the sourcing means;
• means, responsive to a presence of a generated indication of the capability to receive data from these sourcing means and also to a reception of an indication from the downstream receiver means, for transmitting in an upstream direction towards the sourcing means the signal indicating the capability to receive data from the sourcing means;
• and
• a first queue means for storing the generated indication of a capability to receive data from the sourcing means and a second queue means for storing the received signal indicating a capability of the downstream receiver means to receive data from the sourcing means.