Display device and driving method that compensates for unused frame time

• US 8,237,754 B2
• Filed: 01/28/2008
• Issued: 08/07/2012
• Est. Priority Date: 07/27/2007
• Status: Active Grant

• Current Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Original Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Inventors: Kwan, Kin Yip Kenneth, Nguyen, Andrea, Ng, Sunny Yat-san, Zuravleff, William K.
• Primary Examiner(s): Lefkowitz, Sumati
• Assistant Examiner(s): Amadiz, Rodney
• Application Number:
  US12/011,604
• Publication Number:
  US 20090027362A1
• Time in Patent Office: 1,653 Days
• Field of Search: 345 87-100, 345/103, 345/204, 345690-693
• US Class Current: 345/691
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0267 Details of drivers for scan electrodes, other than drivers for liquid crystal, plasma or OLED displays
• CPC Class Codes: G09G 2310/0272 Details of drivers for data electrodes, the drivers communicating data to the pixels by means of a current
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 5/395 Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen G09G5/399 takes precedence

Abstract

A novel method for driving a display having an array of pixels arranged in a plurality of columns and a plurality of rows includes the steps of defining a modulation period for a row of pixels, dividing the modulation period into a number of coequal time intervals equal to n times the number of rows in the array, receiving a multi-bit data word that indicates an intensity value, and updating the signal asserted on the pixel during a plurality of the time intervals such that the intensity value is displayed by the pixel. Note that n is an integer greater than zero. The method can be applied to all rows, which can be driven asynchronously. A display driver for performing the novel methods is also disclosed. The present invention facilitates driving the display at 100% bandwidth efficiency during each time interval in the modulation period.

Claims

1. A method for driving a display device including an array of pixels arranged in a plurality of columns and a plurality of rows, said method comprising:

defining a modulation period during which electrical signals corresponding to particular intensity values will be asserted on the pixels in said rows of said array;

receiving a first frame synchronization signal at the beginning of said modulation period;

dividing said modulation period into a plurality of time intervals;

receiving a second frame synchronization signal that defines a time difference between the end of the last one of said time intervals of said modulation period and receipt of said second frame synchronization signal;

defining a second modulation period;

dividing said second modulation period into said plurality of time intervals;

adjusting the duration of at least some of said time intervals in said second modulation period to spread said time difference over said second modulation period; and

updating a plurality of said rows in said array during said modulation period and said second modulation period such that said particular intensity values are asserted on said pixels in said rows of said array; and

wherein

said step of adjusting the duration of at least some of said time intervals in said second modulation period further comprises using a No-Operation (NOP) fraction to lengthen the duration of at least some of said time intervals by a portion of said time difference; and

the value of said NOP fraction depends on the duration of said time difference.

2. A method according to claim 1, further comprising calculating a value for said NOP fraction based upon the duration of said time difference and the number of times that said rows of said array are updated in said modulation period.

3. A method according to claim 1, wherein said step of using said NOP fraction to lengthen the duration of at least some of said time intervals in said second modulation period includes adding said NOP fraction to an accumulated NOP value each time one of said rows is updated during said second modulation period.

4. A method according to claim 3, further comprising:

generating a reference clock signal including a plurality of clock pulses during said modulation period and said second modulation period; and

wherein

said step of using said NOP fraction to lengthen the duration of at least some of said time intervals in said second modulation period includes outputting a number of NOP operation codes on an instruction bus of said display driver when said accumulated NOP value is greater than a predetermined NOP value; and

each of said NOP operation codes causes at least some components of said display device to ignore a portion of said reference clock signal such that at least some of said time intervals in said second modulation period contain more of said clock pulses than other ones of said time intervals.

5. A method according to claim 4, wherein:

said accumulated NOP value has a whole portion and a fractional portion; and

said step of outputting said number of NOP operation codes includes

outputting NOP operation codes when said accumulated NOP value is greater than or equal to one, and

outputting a number of NOP operation codes equal to said whole portion of said accumulated NOP value.

6. A method according to claim 5, further comprising subtracting said whole portion of said accumulated NOP value from said accumulated NOP value prior to updating another one of said rows in said array.

7. A method according to claim 6, further comprising:

adding said NOP fraction to said accumulated NOP value each time one of said rows is updated during said second modulation period; and

outputting more NOP operation codes when said accumulated NOP value is greater than or equal to one, the number of more NOP operation codes being equal to the whole portion of said accumulated NOP value.

8. A method according to claim 1, further comprising:

receiving a first-of-frame signal indicating the beginning of a first one of said time intervals in said modulation period;

measuring a phase difference between said frame synchronization signal and said first-of-frame signal; and

wherein

said step of adjusting the duration of at least some of said time intervals in said second modulation period further includes adjusting the duration of at least some of said time intervals based on said phase difference in order to synchronize receipt of a subsequent frame synchronization signal and a subsequent first-of-frame signal.

9. A method according to claim 8,

wherein the value of said NOP fraction depends on said time difference and said phase difference.

10. A method according to claim 9, further comprising:

receiving a first-of-frame signal indicating the beginning of a first one of said time intervals in said second modulation period;

measuring a second phase difference between said second frame synchronization signal and said first-of-frame signal in said second modulation period;

comparing said second phase difference with said phase difference; and

adjusting the value of said NOP fraction based upon the difference between said second phase difference and said phase difference.

11. A method according to claim 10, wherein said phase difference and said second phase difference are signed quantities.

12. A method according to claim 10, further comprising:

updating an equal number of rows in each of said modulation period and said second modulation period; and

wherein

adjusting the value of said NOP fraction includes increasing or decreasing said NOP fraction by a NOP fraction adjustment value;

said NOP fraction adjustment value is determined in part by dividing said second phase difference by a constant; and

said constant is a function of the number of said rows that are updated during each of said modulation period and said second modulation period.

13. A method according to claim 12, wherein said NOP fraction adjustment value is a signed quantity.

14. A method according to claim 8, further comprising storing said phase difference.

15. A method according to claim 8, wherein said phase difference is a signed quantity.

16. A method according to claim 9, further comprising:

generating a reference clock signal including a plurality of clock pulses during said modulation period and said second modulation period;

accumulating a NOP value based upon said NOP fraction each time one of said rows is updated during said second modulation period; and

outputting a number of NOP operation codes when said accumulated NOP value is greater than a predetermined value; and

wherein each of said NOP operation codes causes at least some components of said display device to ignore a portion of said reference clock signal such that at least some of said time intervals in said second modulation period contain more of said clock pulses than other ones of said time intervals.

17. A method according to claim 1, wherein:

said frame synchronization signal is a Vsync signal; and

said second frame synchronization signal is a second Vsync signal.

18. A method according to claim 1, further comprising:

receiving a series of clock pulses from a reference clock; and

determining said time difference by counting said clock pulses between the end of the last one of said time intervals in said modulation period and said second frame synchronization signal.

19. A method according to claim 1, wherein said second modulation period is temporally offset from said modulation period.

20. A display driver for driving an array of pixels arranged in a plurality of columns and a plurality of rows, said display driver comprising:

a timer operative to generate a series of time values each associated with a respective one of a plurality of time intervals;

a synchronization input operative to receive a series of frame synchronization signals;

control logic operative to

define a modulation period responsive to receiving a first frame synchronization signal,

divide said modulation period into a plurality of time intervals,

define a second modulation period responsive to receiving a second frame synchronization signal,

divide said second modulation period into said plurality of time intervals, and

update the electrical signals asserted on pixels in a plurality of said rows in said array during said modulation period and said second modulation period such that particular intensity values are asserted on said pixels in each of said modulation period and said second modulation period; and

a compensator operative to adjust the duration of at least some of said time intervals in said second modulation period depending on a time difference between the end of the last one of said time intervals in said modulation period and said second frame synchronization signal; and

wherein

said compensator is further operative to use a No-Operation (NOP) fraction to lengthen the duration of at least some of said time intervals in said second modulation period by a portion of said time difference; and

the value of said NOP fraction depends on the duration of said time difference.

21. A display driver according to claim 20, wherein said compensator is further operative to calculate the value of said NOP fraction based upon the duration of said time difference and the number of rows that said control logic updates during said modulation period.

22. A display driver according to claim 20, wherein said compensator further includes an accumulator operative to add said NOP fraction to an accumulated NOP value each time one of said rows is updated during said second modulation period.

23. A display driver according to claim 22, further comprising:

a reference clock operative to generate a series of reference clock pulses during said modulation period and said second modulation period; and

wherein

said reference clock coordinates the operation of said display driver;

said compensator is operative to lengthen the duration of at least some of said time intervals in said second modulation period by outputting a number of NOP operation codes on an instruction bus of said display driver when said accumulated NOP value is greater than a predetermined value; and

each of said NOP operation codes causes said control logic and said timer to ignore a number of said reference clock pulses such that at least some of said time intervals in said second modulation period contain more of said reference clock pulses than other ones of said time intervals.

24. A display driver according to claim 23, wherein:

said accumulated NOP value has a whole portion and a fractional portion; and

said compensator is operative to output a number of NOP operation codes equal to the whole portion of said accumulated NOP value when said accumulated NOP value is greater than or equal to one.

25. A display driver according to claim 24, wherein said compensator is further operative to subtract said whole portion of said accumulated NOP value from said accumulated NOP value before said control logic updates another one of said rows in said array.

26. A display driver according to claim 25, wherein said compensator is further operative to:

add said NOP fraction to said accumulated NOP value each time another one of said rows is updated during said second modulation period; and

output more NOP operation codes when said accumulated NOP value is greater than or equal to one, the number of more NOP operation codes being equal to said whole portion of said accumulated NOP value.

27. A display driver according to claim 20, further comprising:

a first-of-frame input terminal operative to receive a series of first-of-frame signals, each of said first-of-frame signals indicating the beginning of a first one of said time intervals in one of said modulation period and said second modulation period; and

wherein

said compensator is further operative to

measure a phase difference between said frame synchronization signal and said first-of-frame signal in said modulation period, and

adjust the duration of at least some of said time intervals in said second modulation period based on said phase difference in order to synchronize receipt of a subsequent frame synchronization signal and a subsequent first-of-frame signal.

28. A display driver according to claim 27, wherein the value of said NOP fraction depends on said time difference and said phase difference.

29. A display driver according to claim 28, wherein said compensator is further operative to:

measure a second phase difference between said second frame synchronization signal and said first-of-frame signal in said second modulation period;

compare said second phase difference with said phase difference; and

adjust the value of said NOP fraction based upon the difference between said second phase difference and said phase difference.

30. A display driver according to claim 29, wherein said phase difference and said second phase difference are signed quantities.

31. A display driver according to claim 29, wherein:

said control logic is operative to update an equal number of rows in each of said modulation period and said second modulation period; and

wherein

said compensator is further operative to

determine a NOP fraction adjustment value by dividing said second phase difference by a constant, said constant being a function of the number of said rows that said control logic updates during each of said modulation period and said second modulation period, and

increase or decrease the value of said NOP fraction by said NOP fraction adjustment value.

32. A display driver according to claim 31, wherein said NOP fraction adjustment value is a signed quantity.

33. A display driver according to claim 28, further comprising:

a reference clock operative to generate a series of reference clock pulses during said modulation period and said second modulation period, said reference clock coordinating the operation of said display driver; and

wherein

said compensator is further operative to

accumulate a NOP value based upon said NOP fraction each time said control logic updates one of said rows during said second modulation period, and

output a number of NOP operation codes when said accumulated NOP value is greater than a predetermined value; and

each of said NOP operation codes causes said control logic and said timer to ignore a number of said reference clock pulses such that at least some of said time intervals in said second modulation period contain more of said reference clock pulses than other ones of said time intervals.

34. A display driver according to claim 27, further comprising:

memory for storing data and code; and

wherein

said compensator is further operative to store said phase difference in said memory.

35. A display driver according to claim 27, wherein said phase difference is a signed quantity.

36. A display driver according to claim 20, wherein:

said frame synchronization signal is a Vsync signal; and

said second frame synchronization signal is a second Vsync signal.

37. A display driver according to claim 20, further comprising:

a reference clock operative to generate a series of reference clock pulses during said modulation period and said second modulation period, said reference clock coordinating the operation of said display driver; and

wherein

said compensator is further operative to determine said time difference by counting the number of said clock pulses between the end of the last one of said time intervals in said modulation period and said second frame synchronization signal.

38. A display driver according to claim 20, wherein said control logic is further operative to temporally offset said second modulation period from said modulation period.

39. A method for driving a display device including an array of pixels arranged in a plurality of columns and a plurality of rows, said method comprising:

defining a modulation period during which electrical signals corresponding to particular intensity values will be asserted on the pixels in said rows of said array;

receiving a first frame synchronization signal at the beginning of said modulation period;

dividing said modulation period into a plurality of time intervals;

receiving a first-of-frame signal indicating the beginning of a first one of said time intervals in said modulation period;

measuring a phase difference between said frame synchronization signal and said first-of-frame signal;

receiving a second frame synchronization signal that defines a time difference between the end of the last one of said time intervals of said modulation period and receipt of said second frame synchronization signal;

defining a second modulation period;

dividing said second modulation period into said plurality of time intervals;

adjusting the duration of at least some of said time intervals in said second modulation period to spread said time difference over said second modulation period and to synchronize receipt of a subsequent frame synchronization signal and a subsequent first-of-frame signal based on said phase difference; and

updating a plurality of said rows in said array during said modulation period and said second modulation period such that said particular intensity values are asserted on said pixels in said rows of said array; and

wherein

said step of adjusting the duration of at least some of said time intervals in said second modulation period further comprises using a No-Operation (NOP) fraction to lengthen the duration of at least some of said time intervals; and

the value of said NOP fraction depends on said time difference and said phase difference.

40. A method according to claim 39, further comprising:

receiving a first-of-frame signal indicating the beginning of a first one of said time intervals in said second modulation period;

measuring a second phase difference between said second frame synchronization signal and said first-of-frame signal in said second modulation period;

comparing said second phase difference with said phase difference; and

adjusting the value of said NOP fraction based upon the difference between said second phase difference and said phase difference.

41. A method according to claim 40, wherein said phase difference and said second phase difference are signed quantities.

42. A method according to claim 40, further comprising:

updating an equal number of rows in each of said modulation period and said second modulation period; and

wherein

adjusting the value of said NOP fraction includes increasing or decreasing said NOP fraction by a NOP fraction adjustment value;

said NOP fraction adjustment value is determined in part by dividing said second phase difference by a constant; and

said constant is a function of the number of said rows that are updated during each of said modulation period and said second modulation period.

43. A method according to claim 42, wherein said NOP fraction adjustment value is a signed quantity.

44. A method according to claim 39, further comprising:

generating a reference clock signal including a plurality of clock pulses during said modulation period and said second modulation period;

accumulating a NOP value based upon said NOP fraction each time one of said rows is updated during said second modulation period; and

outputting a number of NOP operation codes when said accumulated NOP value is greater than a predetermined value; and

wherein each of said NOP operation codes causes at least some components of said display device to ignore a portion of said reference clock signal such that at least some of said time intervals in said second modulation period contain more of said clock pulses than other ones of said time intervals.

45. A method according to claim 39, further comprising storing said phase difference.

46. A method according to claim 39, wherein said phase difference is a signed quantity.

47. A method according to claim 39, wherein:

said frame synchronization signal is a Vsync signal; and

said second frame synchronization signal is a second Vsync signal.

48. A method according to claim 39, further comprising:

receiving a series of clock pulses from a reference clock; and

determining said time difference by counting said clock pulses between the end of the last one of said time intervals in said modulation period and said second frame synchronization signal.

49. A method according to claim 39, wherein said second modulation period is temporally offset from said modulation period.

50. A method according to claim 39, further comprising calculating a value for said NOP fraction based upon the duration of said time difference and the number of times that said rows of said array are updated in said modulation period.

51. A method according to claim 39, wherein said step of using said NOP fraction to lengthen the duration of at least some of said time intervals in said second modulation period includes adding said NOP fraction to an accumulated NOP value each time one of said rows is updated during said second modulation period.

52. A method according to claim 51, further comprising:

generating a reference clock signal including a plurality of clock pulses during said modulation period and said second modulation period; and

wherein

said step of using said NOP fraction to lengthen the duration of at least some of said time intervals in said second modulation period includes outputting a number of NOP operation codes on an instruction bus of said display driver when said accumulated NOP value is greater than a predetermined NOP value; and

each of said NOP operation codes causes at least some components of said display device to ignore a portion of said reference clock signal such that at least some of said time intervals in said second modulation period contain more of said clock pulses than other ones of said time intervals.

53. A method according to claim 52, wherein:

said accumulated NOP value has a whole portion and a fractional portion; and

said step of outputting said number of NOP operation codes includes

outputting NOP operation codes when said accumulated NOP value is greater than or equal to one, and

outputting a number of NOP operation codes equal to said whole portion of said accumulated NOP value.

54. A method according to claim 53, further comprising subtracting said whole portion of said accumulated NOP value from said accumulated NOP value prior to updating another one of said rows in said array.

55. A method according to claim 54, further comprising:

adding said NOP fraction to said accumulated NOP value each time one of said rows is updated during said second modulation period; and

outputting more NOP operation codes when said accumulated NOP value is greater than or equal to one, the number of more NOP operation codes being equal to the whole portion of said accumulated NOP value.

56. A display driver for driving an array of pixels arranged in a plurality of columns and a plurality of rows, said display driver comprising:

a timer operative to generate a series of time values each associated with a respective one of a plurality of time intervals;

a synchronization input operative to receive a series of frame synchronization signals;

a first-of-frame input terminal operative to receive a series of first-of-frame signals, each of said first-of-frame signals indicating the beginning of a first one of said time intervals in one of said modulation period and said second modulation period;

control logic operative to

define a modulation period responsive to receiving a first frame synchronization signal,

divide said modulation period into a plurality of time intervals,

define a second modulation period responsive to receiving a second frame synchronization signal,

divide said second modulation period into said plurality of time intervals, and

update the electrical signals asserted on pixels in a plurality of said rows in said array during said modulation period and said second modulation period such that particular intensity values are asserted on said pixels in each of said modulation period and said second modulation period; and

a compensator operative to

measure a phase difference between said frame synchronization signal and said first-of-frame signal in said modulation period, and

adjust the duration of at least some of said time intervals in said second modulation period depending on a time difference between the end of the last one of said time intervals in said modulation period and said second frame synchronization signal and depending on said phase difference to synchronize receipt of a subsequent frame synchronization signal and a subsequent first-of-frame signal; and

wherein

said compensator is operative to use a No-Operation (NOP) fraction to lengthen the duration of at least some of said time intervals in said second modulation period; and

the value of said NOP fraction depends on said time difference and said phase difference.

57. A display driver according to claim 56, wherein said compensator is further operative to:

measure a second phase difference between said second frame synchronization signal and said first-of-frame signal in said second modulation period;

compare said second phase difference with said phase difference; and

adjust the value of said NOP fraction based upon the difference between said second phase difference and said phase difference.

58. A display driver according to claim 57, wherein said phase difference and said second phase difference are signed quantities.

59. A display driver according to claim 57, wherein:

said control logic is operative to update an equal number of rows in each of said modulation period and said second modulation period; and

wherein

said compensator is further operative to

determine a NOP fraction adjustment value by dividing said second phase difference by a constant, said constant being a function of the number of said rows that said control logic updates during each of said modulation period and said second modulation period, and

increase or decrease the value of said NOP fraction by said NOP fraction adjustment value.

60. A display driver according to claim 59, wherein said NOP fraction adjustment value is a signed quantity.

61. A display driver according to claim 56, further comprising:

a reference clock operative to generate a series of reference clock pulses during said modulation period and said second modulation period, said reference clock coordinating the operation of said display driver; and

wherein

said compensator is further operative to

accumulate a NOP value based upon said NOP fraction each time said control logic updates one of said rows during said second modulation period, and

output a number of NOP operation codes when said accumulated NOP value is greater than a predetermined value; and

each of said NOP operation codes causes said control logic and said timer to ignore a number of said reference clock pulses such that at least some of said time intervals in said second modulation period contain more of said reference clock pulses than other ones of said time intervals.

62. A display driver according to claim 56, further comprising:

memory for storing data and code; and

wherein

said compensator is further operative to store said phase difference in said memory.

63. A display driver according to claim 56, wherein said phase difference is a signed quantity.

64. A display driver according to claim 56, wherein:

said frame synchronization signal is a Vsync signal; and

said second frame synchronization signal is a second Vsync signal.

65. A display driver according to claim 56, further comprising:

a reference clock operative to generate a series of reference clock pulses during said modulation period and said second modulation period, said reference clock coordinating the operation of said display driver; and

wherein

said compensator is further operative to determine said time difference by counting the number of said clock pulses between the end of the last one of said time intervals in said modulation period and said second frame synchronization signal.

66. A display driver according to claim 56, wherein said control logic is further operative to temporally offset said second modulation period from said modulation period.

67. A display driver according to claim 56, wherein said compensator is further operative to:

lengthen the duration of at least some of said time intervals in said second modulation period by a portion of said time difference; and

calculate the value of said NOP fraction based upon the number of rows that said control logic updates during said modulation period.

68. A display driver according to claim 56, wherein said compensator is further operative to:

lengthen the duration of at least some of said time intervals in said second modulation period by a portion of said time difference; and

add said NOP fraction to an accumulated NOP value each time one of said rows is updated during said second modulation period.

69. A display driver according to claim 68, further comprising:

a reference clock operative to generate a series of reference clock pulses during said modulation period and said second modulation period; and

wherein

said reference clock coordinates the operation of said display driver;

said compensator is operative to lengthen the duration of at least some of said time intervals in said second modulation period by outputting a number of NOP operation codes on an instruction bus of said display driver when said accumulated NOP value is greater than a predetermined value; and

each of said NOP operation codes causes said control logic and said timer to ignore a number of said reference clock pulses such that at least some of said time intervals in said second modulation period contain more of said reference clock pulses than other ones of said time intervals.

70. A display driver according to claim 69, wherein:

said accumulated NOP value has a whole portion and a fractional portion; and

said compensator is operative to output a number of NOP operation codes equal to the whole portion of said accumulated NOP value when said accumulated NOP value is greater than or equal to one.

71. A display driver according to claim 70, wherein said compensator is further operative to subtract said whole portion of said accumulated NOP value from said accumulated NOP value before said control logic updates another one of said rows in said array.

72. A display driver according to claim 71, wherein said compensator is further operative to:

add said NOP fraction to said accumulated NOP value each time another one of said rows is updated during said second modulation period; and

output more NOP operation codes when said accumulated NOP value is greater than or equal to one, the number of more NOP operation codes being equal to said whole portion of said accumulated NOP value.

73. A non-transitory, electronically-readable storage medium having code embodied therein for causing an electronic device to:

define a modulation period during which electrical signals corresponding to particular intensity values will be asserted on pixels in rows of an array;

receive a first frame synchronization signal at the beginning of said modulation period;

divide said modulation period into a plurality of time intervals;

receive a second frame synchronization signal that defines a time difference between the end of the last one of said time intervals of said modulation period and receipt of said second frame synchronization signal;

define a second modulation period;

divide said second modulation period into said plurality of time intervals;

adjust the duration of at least some of said time intervals in said second modulation period to spread said time difference over said second modulation period; and

update a plurality of said rows in said array during said modulation period and said second modulation period such that said particular intensity values are asserted on said pixels in said rows of said array; and

wherein

said code is operative to cause said electronic device to adjust the duration of at least some of said time intervals in said second modulation period by using a No-Operation (NOP) fraction to lengthen the duration of at least some of said time intervals by a portion of said time difference; and

the value of said NOP fraction depends on the duration of said time difference.

74. A non-transitory, electronically-readable storage medium according to claim 73, wherein said code is further operative to calculate a value for said NOP fraction based upon the duration of said time difference and the number of times that said rows of said array are updated in said modulation period.

75. A non-transitory, electronically-readable storage medium according to claim 73, wherein said code is operative to cause said electronic device to use said NOP fraction to lengthen the duration of at least some of said time intervals in said second modulation period by adding said NOP fraction to an accumulated NOP value each time one of said rows is updated during said second modulation period.

76. A non-transitory, electronically-readable storage medium according to claim 75, wherein:

said code is further operative to cause said electronic device to use said NOP fraction to lengthen the duration of at least some of said time intervals in said second modulation period by outputting a number of NOP operation codes on an instruction bus of said display driver when said accumulated NOP value is greater than a predetermined NOP value;

a reference clock signal including a plurality of clock pulses is generated during said modulation period and said second modulation period; and

each of said NOP operation codes causes at least some components of said electronic device to ignore a portion of said reference clock signal such that at least some of said time intervals in said second modulation period contain more of said clock pulses than other ones of said time intervals.

77. A non-transitory, electronically-readable storage medium according to claim 76, wherein:

said accumulated NOP value has a whole portion and a fractional portion; and

said code is further operative to cause said electronic device to

output NOP operation codes when said accumulated NOP value is greater than or equal to one, and

output a number of NOP operation codes equal to said whole portion of said accumulated NOP value.

78. A non-transitory, electronically-readable storage medium according to claim 77, wherein said code is further operative to cause said electronic device to subtract said whole portion of said accumulated NOP value from said accumulated NOP value prior to updating another one of said rows in said array.

79. A non-transitory, electronically-readable storage medium according to claim 78, wherein said code is further operative to cause said electronic device to:

add said NOP fraction to said accumulated NOP value each time one of said rows is updated during said second modulation period; and

output more NOP operation codes when said accumulated NOP value is greater than or equal to one, the number of more NOP operation codes being equal to the whole portion of said accumulated NOP value.

80. A non-transitory, electronically-readable storage medium according to claim 73, wherein said code is further operative to cause said electronic device to:

receive a first-of-frame signal indicating the beginning of a first one of said time intervals in said modulation period;

measure a phase difference between said frame synchronization signal and said first-of-frame signal; and

adjust the duration of at least some of said time intervals in said second modulation period further by adjusting the duration of at least some of said time intervals based on said phase difference in order to synchronize receipt of a subsequent frame synchronization signal and a subsequent first-of-frame signal.

81. A non-transitory, electronically-readable storage medium according to claim 80, wherein the value of said NOP fraction depends on said time difference and said phase difference.

82. A non-transitory, electronically-readable storage medium according to claim 81, wherein said code is further operative to cause said electronic device to:

receive a first-of-frame signal indicating the beginning of a first one of said time intervals in said second modulation period;

measure a second phase difference between said second frame synchronization signal and said first-of-frame signal in said second modulation period;

compare said second phase difference with said phase difference; and

adjust the value of said NOP fraction based upon the difference between said second phase difference and said phase difference.

83. A non-transitory, electronically-readable storage medium according to claim 82, wherein said phase difference and said second phase difference are signed quantities.

84. A non-transitory, electronically-readable storage medium according to claim 82, wherein:

said code is further operative to cause said electronic device to

update an equal number of rows in each of said modulation period and said second modulation period, and

adjust the value of said NOP fraction by increasing or decreasing said NOP fraction by a NOP fraction adjustment value;

said NOP fraction adjustment value is determined in part by dividing said second phase difference by a constant; and

said constant is a function of the number of said rows that are updated during each of said modulation period and said second modulation period.

85. A non-transitory, electronically-readable storage medium according to claim 84, wherein said NOP fraction adjustment value is a signed quantity.

86. A non-transitory, electronically-readable storage medium according to claim 81, wherein:

said code is further operative to cause said electronic device to

accumulate a NOP value based upon said NOP fraction each time one of said rows is updated during said second modulation period, and

output a number of NOP operation codes when said accumulated NOP value is greater than a predetermined value;

a reference clock signal including a plurality of clock pulses is generated during said modulation period and said second modulation period; and

each of said NOP operation codes causes at least some components of said electronic device to ignore a portion of said reference clock signal such that at least some of said time intervals in said second modulation period contain more of said clock pulses than other ones of said time intervals.

87. A non-transitory, electronically-readable storage medium according to claim 80, wherein said code is further operative to cause said electronic device to store said phase difference.

88. A non-transitory, electronically-readable storage medium according to claim 80, wherein said phase difference is a signed quantity.

89. A non-transitory, electronically-readable storage medium according to claim 73, wherein:

said frame synchronization signal is a Vsync signal; and

said second frame synchronization signal is a second Vsync signal.

90. A non-transitory, electronically-readable storage medium according to claim 73, wherein said code is further operative to cause said electronic device to:

receive a series of clock pulses from a reference clock; and

determine said time difference by counting said clock pulses between the end of the last one of said time intervals in said modulation period and said second frame synchronization signal.

91. A non-transitory, electronically-readable storage medium according to claim 73, wherein said second modulation period is temporally offset from said modulation period.

92. A non-transitory, electronically-readable storage medium having code embodied therein for causing an electronic device to:

define a modulation period during which electrical signals corresponding to particular intensity values will be asserted on pixels in rows of an array;

receive a first frame synchronization signal at the beginning of said modulation period;

divide said modulation period into a plurality of time intervals;

receive a first-of-frame signal indicating the beginning of a first one of said time intervals in said modulation period;

measure a phase difference between said frame synchronization signal and said first-of-frame signal;

receive a second frame synchronization signal that defines a time difference between the end of the last one of said time intervals of said modulation period and receipt of said second frame synchronization signal;

define a second modulation period;

divide said second modulation period into said plurality of time intervals;

adjust the duration of at least some of said time intervals in said second modulation period to spread said time difference over said second modulation period and to synchronize receipt of a subsequent frame synchronization signal and a subsequent first-of-frame signal based on said phase difference; and

update a plurality of said rows in said array during said modulation period and said second modulation period such that said particular intensity values are asserted on said pixels in said rows of said array; and

wherein

said code is operative to cause said electronic device to adjust the duration of at least some of said time intervals in said second modulation period by using a No-Operation (NOP) fraction to lengthen the duration of at least some of said time intervals; and

the value of said NOP fraction depends on said time difference and said phase difference.

93. A non-transitory, electronically-readable storage medium according to claim 92, wherein said code is further operative to cause said electronic device to:

receive a first-of-frame signal indicating the beginning of a first one of said time intervals in said second modulation period;

measure a second phase difference between said second frame synchronization signal and said first-of-frame signal in said second modulation period;

compare said second phase difference with said phase difference; and

adjust the value of said NOP fraction based upon the difference between said second phase difference and said phase difference.

94. A non-transitory, electronically-readable storage medium according to claim 93, wherein said phase difference and said second phase difference are signed quantities.

95. A non-transitory, electronically-readable storage medium according to claim 93, wherein:

said code is further operative to cause said electronic device to;

update an equal number of rows in each of said modulation period and said second modulation period, and

adjust the value of said NOP fraction by increasing or decreasing said NOP fraction by a NOP fraction adjustment value;

said NOP fraction adjustment value is determined in part by dividing said second phase difference by a constant; and

said constant is a function of the number of said rows that are updated during each of said modulation period and said second modulation period.

96. A non-transitory, electronically-readable storage medium according to claim 95, wherein said NOP fraction adjustment value is a signed quantity.

97. A non-transitory, electronically-readable storage medium according to claim 92, wherein:

said code is further operative to cause said electronic device to

accumulate a NOP value based upon said NOP fraction each time one of said rows is updated during said second modulation period, and

output a number of NOP operation codes when said accumulated NOP value is greater than a predetermined value;

a reference clock signal including a plurality of clock pulses is generated during said modulation period and said second modulation period; and

each of said NOP operation codes causes at least some components of said electronic device to ignore a portion of said reference clock signal such that at least some of said time intervals in said second modulation period contain more of said clock pulses than other ones of said time intervals.

98. A non-transitory, electronically-readable storage medium according to claim 92, wherein said code is further operative to cause said electronic device to store said phase difference.

99. A non-transitory, electronically-readable storage medium according to claim 92, wherein said phase difference is a signed quantity.

100. A non-transitory, electronically-readable storage medium according to claim 92, wherein:

said frame synchronization signal is a Vsync signal; and

said second frame synchronization signal is a second Vsync signal.

101. A non-transitory, electronically-readable storage medium according to claim 92, wherein said code is further operative to cause said electronic device to:

receive a series of clock pulses from a reference clock; and

determine said time difference by counting said clock pulses between the end of the last one of said time intervals in said modulation period and said second frame synchronization signal.

102. A non-transitory, electronically-readable storage medium according to claim 92, wherein said second modulation period is temporally offset from said modulation period.

103. A non-transitory, electronically-readable storage medium according to claim 92, wherein said code is further operative to cause said electronic device to calculate a value for said NOP fraction based upon the duration of said time difference and the number of times that said rows of said array are updated in said modulation period.

104. A non-transitory, electronically-readable storage medium according to claim 92, wherein said code is operative to cause said electronic device to use said NOP fraction to lengthen the duration of at least some of said time intervals in said second modulation period by adding said NOP fraction to an accumulated NOP value each time one of said rows is updated during said second modulation period.

105. A non-transitory, electronically-readable storage medium according to claim 104, wherein:

said code is further operative to cause said electronic device to use said NOP fraction to lengthen the duration of at least some of said time intervals in said second modulation period by outputting a number of NOP operation codes on an instruction bus of said electronic device when said accumulated NOP value is greater than a predetermined NOP value;

a reference clock signal including a plurality of clock pulses is generated during said modulation period and said second modulation period; and

each of said NOP operation codes causes at least some components of said electronic device to ignore a portion of said reference clock signal such that at least some of said time intervals in said second modulation period contain more of said clock pulses than other ones of said time intervals.

106. A non-transitory, electronically-readable storage medium according to claim 105, wherein:

said accumulated NOP value has a whole portion and a fractional portion; and

said code is further operative to cause said electronic device to

output NOP operation codes when said accumulated NOP value is greater than or equal to one, and

output a number of NOP operation codes equal to said whole portion of said accumulated NOP value.

107. A non-transitory, electronically-readable storage medium according to claim 106, wherein said code is further operative to cause said electronic device to subtract said whole portion of said accumulated NOP value from said accumulated NOP value prior to updating another one of said rows in said array.

108. A non-transitory, electronically-readable storage medium according to claim 107, wherein said code is further operative to cause said electronic device to:

add said NOP fraction to said accumulated NOP value each time one of said rows is updated during said second modulation period; and

output more NOP operation codes when said accumulated NOP value is greater than or equal to one, the number of more NOP operation codes being equal to the whole portion of said accumulated NOP value.