Packed bus selection of multiple pixel depths in palette devices, systems and methods

A computer graphics system comprising:

• a digital computer;
• a video memory connected to said digital computer and operable to store color codes for information in a video image;
• a bus having a width and connected to an output of said video memory;
• and
• a palette device connected to said video memory by said bus and including:
• a multiple-bit input for simultaneous entry of multiple color codes from the bus;
• an input latch connected to said multiple-bit input for temporarily storing color codes received at said multiple-bit input;
• a look-up table memory for supplying color data words in response to the color codes from said input latch;
• and
• color code transfer circuitry including a control register loadable by said digital computer storing a number of bits per color code and a number of color codes per bus cycle, and a multiplexer connected to said control register and connected between said input latch and said look-up table memory, said multiplexer supplying said look-up table memory with a sequence of a predetermined block of bits of data stored in said input latch, said block of bits being equal in number to said number of bits per color code stored in said control register thereby transferring individual ones of said multiple color codes from said input latch, said sequence continuing for a number block of bits equal in number to said number of color codes per bus cycle store in said control register for each loading of said input latch from said multiple-bit input, whereby said multiple color codes have a width selectable by said digital computer and pack the entire width of the bus.

A computer graphics system for use with a digital computer, comprising:

• a video memory having an input for connection to the digital computer and operable to store color codes for information in a video image;
• a bus having a width and connected to an output of said video memory;
• and
• a palette device connected by said bus to said video memory for transfer of color codes to the palette device, said palette device comprising:
• a multiple-bit input for simultaneous entry of multiple color codes from the bus;
• an input latch connected to said multiple-bit input for temporarily storing color codes received at said multiple-bit input;
• a look-up table memory for supplying color data words in response to the color codes from the input latch;
• and
• color code transfer circuitry including an externally loadable control register storing a number of bits per color code and a number of color codes per bus cycle, and a multiplexer circuitry connected to said control register and connected between said input latch and said look-up table memory, said multiplexer supplying said look-up table memory with a sequence of a predetermined block of bits of data stored in said input latch, said block of bits being equal in number to said number of bits per color code stored in said control register thereby transferring individual ones of said multiple color codes from said input latch, said sequence continuing for a number block of bits equal in number to said number of color codes per bus cycle store in said control register for each loading of said input latch from said multiple-bit input, whereby said multiple color codes pack the entire width of the bus.

A facsimile system comprising:

• a light sensing device adapted to produce an electrical input signal in response to an image presented to said light sensing device;
• a processing circuit connected to said light sensing device to generate color codes representing color information in response to the image;
• a bus having a width and connected to said processing circuit to simultaneously carry the color codes;
• a palette device connected by said bus to said video memory for transfer of color codes to the palette device, said palette device comprising:
• a multiple-bit input for simultaneous entry of multiple color codes from the bus;
• an input latch connected to said multiple-bit input for temporarily storing color codes received at said multiple-bit input;
• a look-up table memory for supplying color data words in response to the color codes from the input latch;
• and
• color code transfer circuitry including an externally loadable control register storing a number of bits per color code and a number of color codes per bus cycle, and a multiplexer connected to said control register and connected between said input latch and said look-up table memory, said multiplexer supplying said look-up table memory with a sequence of a predetermined block of bits of data stored in said input latch, said block of bits being equal in number to said number of bits per color code stored in said control register thereby transferring individual ones of said multiple color codes from said input latch, said sequence continuing for a number block of bits equal in number to said number of color codes per bus cycle store in said control register for each loading of said input latch from said multiple-bit input, whereby said multiple color codes pack the entire width of the bus;
• said facsimile system further comprising a color display device connected to said palette device and responsive to said color data words to produce a color display;
• and
• a modem circuit connected to said processor circuit to couple the color information to a communications path.

A printer system comprising:

• a processing circuit adapted to generate color codes representing color information in an image;
• a bus having a bus width and connected to said processing circuit to simultaneously carry multiple color codes;
• a palette device connected by said processing circuit via said bus for transfer of the color codes to said palette device, said palette device comprising:
• a multiple-bit input for simultaneous entry of the multiple color codes from the bus;
• an input latch connected to said multiple-bit input for temporarily storing color codes received at said multiple-bit input;
• a look-up table memory for supplying color data words in response to the color codes from said input latch;
• and
• color code transfer circuitry including an externally loadable control register storing a number of bits per color code and a number of color codes per bus cycle, and a multiplexer connected to said control register and connected between said input latch and said look-up table memory, said multiplexer supplying said look-up table memory with a sequence of a predetermined block of bits of data stored in said input latch, said block of bits being equal in number to said number of bits per color code stored in said control register thereby transferring individual ones of said multiple color codes from said input latch, said sequence continuing for a number block of bits equal in number to said number of color codes per bus cycle store in said control register for each loading of said input latch from said multiple-bit input, whereby said multiple color codes pack the entire width of the bus.
• said printer system further comprising a color display device and responsive to said color data words to produce a color display;
• and
• a color printer assembly responsive to said processing circuit to make a print of the image with the color information.

A method of operating a palette device controllable by a digital computer with a video memory to produce signals representing color for a color display device, the method comprising the steps of:

• entering multiple color codes simultaneously from the video memory into a multiple-bit input in the palette device via a bus having a bus width, said multiple color codes packing the entire width of the bus;
• storing a number of bits per color code and a number of color codes per bus cycle in a control register;
• and
• sequentially transferring individual ones of said multiple color codes of selectable width equal to the number of bits per color code stored in the control register from the multiple-bit input to a look-up table memory, said sequential transfer including a number of color codes equal to the number of color codes per bus cycle stored in the control register for supplying color data words in response to the individual color codes from the multiple-bit input.