Controlled delay devices, systems and methods

• US 5,293,468 A
• Filed: 08/06/1992
• Issued: 03/08/1994
• Est. Priority Date: 06/27/1990
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Guttag, Karl M., Nye, Jeffrey L.
• Primary Examiner(s): Nguyen, Phu K.
• Application Number:
  US07/925,885
• Time in Patent Office: 579 Days
• Field of Search: 340/706, 340/703, 340/721, 340/726, 340/734, 340/799, 358/150, 358/183, 395/129, 395/131, 395/162, 395/164
• US Class Current: 345/593
• CPC Class Codes: G09G 2360/123 using interleaving
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/06 using colour palettes, e.g. look-up tables
• CPC Class Codes: G09G 5/363 Graphics controllers
• CPC Class Codes: G09G 5/39 Control of the bit-mapped memory

Abstract

A palette device for use with circuitry that produces color codes and a video control signal. The palette device includes a mode circuit establishing one of a plurality of different operating modes, and color code processing circuitry operable according to a mode established by the mode circuit and responsive to the color codes to supply color data words that are convertible to analog form. Depending on the different modes, the color code processing circuitry establishes different time intervals between input of the color codes to the color code processing circuitry and supplying of color data words. A digital to analog converter connected to said color code processing circuitry receives the color data words and converts them to an analog video signal. A variable delay circuit responsive to said mode circuit delays the video control signal by a time interval depending on the mode established by the mode circuit, and the variable delay circuit is connected to control the digital to analog converter with the video control signal thus delayed. Palette devices, computer graphics systems, facsimile systems, printer systems and methods are disclosed.

Claims

1. A palette device for use with circuitry that produces color codes and a video control signal, the palette device comprising:

a mode circuit establishing one of a plurality of different operating modes, said mode circuit having a programmable register to adjust a video resolution by varying clock frequencies, to configure said mode circuit according to an amount of available memory providing the color codes, and to control operation of the device, each of said operating modes determined by a selectable bit length of the color codes and a selectable bus width for receipt of the color codes;

color code processing circuitry operable according to a mode established by said mode circuit and responsive to the color codes to supply color data words that are convertible to analog form, wherein said color code processing circuitry establishes different time intervals between input of the color codes to said color code processing circuitry and supplying of said color data words depending on said bus width for and said bit length of the color codes;

a digital to analog converter connected to said color code processing circuitry and operable to receive said color data words and convert said color data words to an analog color signal; and

a variable delay circuit responsive to said mode circuit to delay the video control signal by a time interval depending on said mode established by said mode circuit, said variable delay circuit connected to control said digital to analog converter with the video control signal thus delayed.

2. The palette device of claim 1 wherein said digital to analog converter has a blanking input for driving said analog color signal to a blank level, and said variable delay circuit is connected to said blanking input to control said digital to analog converter with the video control signal thus delayed.

3. The palette device of claim 1 wherein said color code processing circuitry includes an input latch to hold the color codes and a look-up table emory to convert the color codes to said color data words.

4. The palette device of claim 3 wherein said color code processing circuitry further includes a selector circuit responsive to said mode circuit to sequentially deliver different sets of bits from said input latch to said look-up table memory, the sequential delivery making said time interval in the color code processing circuitry different depending on said mode established by said mode circuit.

5. The palette device of claim 4 wherein a time for sequential delivery varies directly with a number of pixels per bus load to said input latch.

6. The palette device of claim 4 wherein said variable delay circuit provides a delay which varies from mode to mode in correspondence with an amount by which a time for sequential delivery in said selector circuit varies from mode to mode.

7. The palette device of claim 1 wherein the palette device includes a clock control circuit supplying clock pulses, and said variable delay circuit includes a series of flip-flops clocked by said clock pulses from said clock control circuit, the series of flip-flops connected from an input for said video control signal to said digital to analog converter.

8. The palette device of claim 7 wherein said clock control circuit supplies said clock pulses on a plurality of lines carrying clock pulses of different periods, said lines connected to different flip-flops in said series of flip-flops.

9. The palette device of claim 8 wherein said lines carrying clock pulses of different periods are connected to said flip-flops in order of decreasing period in a direction of increasing delay in said series of flip-flops.

10. The palette device of claim 1 and further comprising a single semiconductor chip having said mode circuit, said color code processing circuitry, said digital to analog converter, and said variable delay circuit fabricated on said single semiconductor chip as an integrated circuit.

11. The palette device of claim 10 wherein said variable delay circuit includes a sync delay circuit connected between a sync input and a sync output of said chip.

12. A computer graphics system comprising:

a digital computer operable to produce a video control signal;

a video memory connected to said digital computer and operable to store color codes for information in a video image; and

a palette device connected to said video memory for transfer of color codes to the palette device, said palette device including;

a mode circuit responsive to said digital computer to establish one of a plurality of different operating modes, said mode circuit having a programmable register to adjust a video resolution by varying a clock frequency, to configure said mode circuit according to an amount of said video memory available, and to control operation of said palette device, each of said operating modes determined by a selectable bit length of the color codes and a selectable bus width for receipt of the color codes from said video memory;

color code processing circuitry operable according to a mode established by said mode circuit and responsive to the color codes from said video memory to supply color data words that are convertible to analog form, wherein said color code processing circuitry established different time intervals between input of the color codes to said color code processing circuitry and supplying of said color data words depending on said bus width for and said bit length of the color codes;

a digital to analog converter connected to said color code processing circuitry to receive said color data words and convert said color data words to an analog vide signal; and

a variable delay circuit responsive to said mode circuit to delay said video control signal by a time interval depending on said mode established by said mode circuit, said variable delay circuit connected to control said digital to analog converter with said video control signal thus delayed.

13. The computer graphics system of claim 12 wherein said palette device includes a clock control circuit connected to provide clock pulses for operating said palette device and further connected by at least one line from said palette device to said digital computer to supply said clock pulses originating from said clock control circuit to said digital computer.

14. The computer graphics system of claim 13 wherein said digital computer includes a circuit responsive to said clock pulses from said palette device to produce said video control signal to said palette device.

15. The computer graphics system of claim 12 and further comprising a video monitor coupled to said palette device.

16. The computer graphics system of claim 12 wherein said digital computer comprises a graphics processor.

17. The computer graphics system of claim 12 wherein said digital computer comprises a host computer and a graphics processor connected to said host computer, to said video memory, and to said palette device.

18. The computer graphics system of claim 12 and further comprising a color display device responsive to said palette device.

19. A computer graphics system for use with a digital computer supplying control information and a video control signal, comprising:

a video memory having an input for connection to the digital computer and operable to store color codes for graphics information; and

a palette device connected to said video memory for transfer of said color codes from said video memory to said palette device, said palette device including;

a mode circuit responsive to the control information to establish one of a plurality of different operating modes said mode circuit having a programmable register to adjust a video resolution by varying a clock frequency, to configure said mode circuit according to an amount of said video memory available, and to control operation of said palette device, each of said operating modes determined by a selectable bit length of the color codes and a selectable bus width for receipt of the color codes from said video memory;

color code processing circuitry operable according to a mode established by said mode circuit and responsive to said color codes from said video memory to supply color data words that are convertible to analog form, wherein said color code processing circuitry establishes different time intervals between input of said color codes to said color code processing circuitry and supplying of said color data words depending on said bus width for and said bit length of the color codes;

a digital to analog converter connected to said color code processing circuitry to receive said color data words and convert said color data words to an analog color signal; and

a variable delay circuit responsive to said mode circuit to delay the video control signal by a time interval a length of which differs in at least two different modes established by said mode circuit, said variable delay circuit connected to control said digital to analog converter with the video control signal thus delayed.

20. The computer graphics system of claim 19 wherein said palette device includes a clock control circuit connected to provide clock pulses for operating said palette device and further connected by at least one line from said palette device to said video memory to supply said clock pulses originating from said clock control circuit to said video memory.

21. The computer graphics system of claim 19 and further comprising a color display device responsive to said analog color signal to produce a color display.

22. 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 a display control signal and color codes representing color information in response to said image;

a palette device connected to said processing circuit for transfer of said color codes to said palette device, said palette device including;

a mode circuit responsive to said processing circuit to establish one of a plurality of different operating modes, said mode circuit having a programmable register to adjust a video resolution by varying a clock frequency, to configure said mode circuit according to an amount of available memory, and to control operation of said palette device, each of said operating modes determined by a selectable bit length of the color codes and a selectable bus width for receipt of the color codes;

color code processing circuitry operable according to a mode established by said mode circuit and responsive to said color codes from said processing circuit to supply color data words that are convertible to analog form, wherein said color code processing circuitry establishes different time intervals between input of said color codes to said color code processing circuitry and supplying of said color data words depending on said bus width for and said bit length of the color codes;

a digital to analog converter connected to said color code processing circuitry to receive said color data words and convert said color data words to an analog color signal; and

a variable delay circuit responsive to said mode circuit to delay said display control signal by a time interval a length of which differs in at least two different modes established by said mode circuit, said variable delay circuit connected to control said digital to analog converter with said display control signal thus delayed;

said facsimile system further comprising a color display device connected to said palette device and responsive to said analog color signal to produce a color display; and

a modem circuit connected to said process circuit to couple said color information in said color data words to a communications path.

23. The facsimile system of claim 22 wherein said palette device includes a clock control circuit connected to provide clock pulses for operating said palette device and further connected by lines from said palette device to said processing circuit to supply said clock pulses originating from said clock control circuit to said processing circuit.

24. The facsimile system of claim 23 wherein said processing circuit includes a circuit responsive to said clock pulses from said palette device to produce said display control signal to said palette device.

25. The facsimile system of claim 22 wherein said color display device includes a color printer.

26. The facsimile system of claim 22 wherein said color display device includes a color video monitor.

27. A printer system comprising:

a processing circuit adapted to generate a display control signal and color codes representing color information in an image;

a palette device controllable by said processing circuit so that said color codes are transferable to said palette device, said palette device including;

a mode circuit responsive to the processing circuit to establish one of a plurality of different operating modes, said mode circuit having a programmable register to adjust a video resolution by varying a clock frequency, to configure said mode circuit according to an amount of available memory, and to control operation of said palette device, each of said operating modes determined by a selectable bit length of the color codes and a selectable bus width for receipt of the color codes;

color code processing circuitry operable according to a mode established by said mode circuit and responsive to said color codes from said processing circuit to supply color data words that are convertible to analog form, wherein said color code processing circuitry establishes different time intervals between input of said color codes to said color code processing circuitry and supplying of said color data words depending on said bus width for and said bit length of the color codes;

a digital to analog converter connected to said color code processing circuitry to receive said color data words and convert said color data words to an analog color signal; and

a variable delay circuit responsive to said mode circuit to delay said display control signal by a time interval a length of which differs in at least two different modes established by said mode circuit, said variable delay circuit connected to control said digital to analog converter with said display control signal thus delayed;

said printer system further comprising a color display device connected to said palette device and responsive to said analog color signal and said display control signal thus delayed 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.

28. The printer system of claim 27 wherein said palette device includes a clock control circuit connected to provide clock pulses for operating said palette device and further connected by at least one line from said palette device to said processing circuit to supply said clock pulses originating from said clock control circuit to said processing circuit.

29. The printer system of claim 28 wherein said processing circuit includes a circuit responsive to said clock pulses from said palette device to produce said display controls signal to said palette device.

30. The printer system of claim 27 and further comprising a light sensing assembly connected to said processing circuit and sensitive to an object to derive said color information for color copying of said object as a print from said color printer assembly.

31. The printer system of claim 30 wherein said light sensing assembly includes a video camera.

32. The printer system of claim 30 wherein said light sensing assembly includes optics and charge-coupled device sensing elements to acquire an image of a document for color copying of said document as a print from said color printer assembly.

33. The printer system of claim 27 and further comprising a modem circuit connected to said processing circuit to couple said color information to a communications path.

34. A method of operating a palette device controllable by a digital computer with a video memory supplying color codes and the digital computer supplying a video control signal to the palette device to produce signals representing color for a video monitor, the method comprising the steps of:

programming the device to control the signals produced for the video monitor;

processing the color codes according to different modes established by the digital computer to supply color data words, each of said modes determined by a selectable bit length of the color codes and a selectable bus width for receipt of the color codes, wherein said processing step establishes different time intervals between input of the color codes for processing and supply of said color data words depending on said bus width for and said bit length of the color codes;

variably delaying the video control signal concurrently with said processing step by time intervals correlated in at least two of said different modes to said time intervals of said processing step thereby to supply the video control signal thus delayed;

converting said color data words to an analog video signal; and

blanking said analog video signal in response to the video control signal thus delayed.

35. A palette device for use with circuitry that produces color codes and a blanking signal, the palette device comprising:

color code processing circuitry responsive to the color codes to supply color data words that are convertible to analog form;

a digital to analog converter connected to said color code processing circuitry to receive said color data words and convert said color data words to an analog signal, said converter having a blanking input for driving said analog signal to a blank level; and

a blanking circuit having the blanking signal as an input and having a plurality of serially connected flip-flops clocked to sample said blanking signal at progressively higher time resolutions in order to feed said blanking input of said digital to analog converter; and

a programmable register to control operation of the palette device.

36. The palette device of claim 35 wherein the blanking signal has a first level and a second level and a transition period for transition from said first level to said second level, and said palette device further includes a circuit for supplying a first clock signal having a period in excess of said transition period to one of said serially connected flip-flops.

37. The palette device of claim 35 and further comprising a clock circuit providing to said flip-flops a video clock signal having a first period, and a dot clock signal having a second period that is shorter than said first period.

38. The palette device of claim 37 wherein said clock circuit further provides a third clock signal having a period intermediate in duration compared to said first and second periods, said flip-flops including an intermediate flip-flop connected to said clock circuit to receive said third clock signal.

39. The palette device of claim 35 further comprising a mode circuit establishing one of a plurality of operating modes for said color code processing circuitry, wherein said color code processing circuitry has different time intervals between input of the color codes and supplying of said color data words depending on said mode established by said mode circuit, said blanking circuit further including a variable delay circuit connected to said flip-flops and responsive to said mode circuit.

40. A computer graphics system comprising:

a digital computer for producing a blanking signal;

a video memory connected to said digital computer and operable to store color codes for color information in an image; and

a palette device connected to said video memory for transfer of color codes to said palette device, said palette device including;

color code processing circuitry responsive to said color codes to supply color data words that are convertible to analog form;

a digital to analog converter connected to said color code processing circuitry to receive said color data words and convert said color data words to an analog signal, said converter having a blanking input for driving said analog signal to a blank level;

a clock circuit connected to provide clock pulses for operating said palette device and further connected to said digital computer to supply clock pulses to said digital computer; and

a blanking circuit having said blanking signal as an input and having a plurality of serially connected flip-flops clocked by said clock circuit to sample said blanking signal at progressively higher time resolutions in order to feed said blanking input of said digital to analog converter; and

a programmable register to control operation of the palette device.

41. The computer graphics system of claim 40 wherein said palette device further includes a mode circuit establishing one of a plurality of operating modes for said color code processing circuitry, wherein said color code processing circuitry has different time intervals between input of said color codes and supplying of said color data words depending on said mode established by said mode circuit, said blanking circuit further including a variable delay circuit connected to said flip-flops and responsive to said mode circuit.