CS9211 datasheet(27/62 Pages) NSC

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Functional Description (Continued)

Table3-10is anexample of oneof the three32 x 64 FRM-

Sequence tables that is addressed by the most significant

bit of the incoming pixel value. The ”n” most-significant bits

(as chosen by Offset 40Ch[6:4]) of each color component

of each incoming pixel looks up one of the 64-bit words

from this table. The number of 1’s in each 64-bit word

determines how bright the pixel will be when that word is

chosen. A word with all zeros will never illuminate the given

pixel in that color, therefore the pixel will be black. A word

with only one “1” will illuminate the given pixel one frame

out of 64, so the pixel will be as dim as possible without

being off entirely. A word with 10 “1”s will illuminate the

given pixel 10 frames out of 64. A word with 64 “1”s will illu-

minate the given pixel in each of the 64 frames, so that

pixel will be as bright as possible.

The Freq (frequency ratio) indicates the number of 0 to 1

transitions within 64 frames. This value multiplied by the

refresh rate will give the frequency of frame rate modula-

tion of a particular intensity. Higher frequency frame rate

modulation will result in better picture quality. The Int

(intensity) column indicates the duty cycle of the primary

color.

The intensity level of this FRM table starts from 0/64 and

gradually increases to 16/64 instead of jumping directly to

16/64. It seems that the human eye is less sensitive to fre-

quency variation at low intensity. As the intensity level

increases, it increases slowly from 16/64 to 48/64 to create

a smooth transition of intensities. The full scale intensity

level is truncated at 48/64 intentionally; above this point the

differences between levels start to become visible. There is

a trade-off between maximum intensity level and smooth

gradations of color.

The generation of FRM tables suitable for driving a particu-

lar display panel in a particular application requires a good

understanding of human vision and significant experimen-

tation. Good candidate patterns for these tables will have

1’s separated by equal numbers of 0’s throughout the word,

instead of clumping all the 1’s together in a particular loca-

tion. Successive values should increase monotonically. All

three tables may be identically or individually programmed.

Table 3-10. Example FRM RAM Table for One Color Component

Col

Frame Count from 0 to 63

Freq

Int

00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000

0/64

00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000

0/64

00000001,00000001,00000001,00000001,00000001,00000001,00000001,00000001

8/64

00000010,00001000,00010000,01000001,00000010,00001000,00010000,01000001

10/64

00010001,00010001,00010001,00010001,00010001,00010001,00010001,00010001

16/64

00010010,01001001,00100100,10010010,01001001,00100100,10010010,01001001

21/64

00100100,10010100,10010010,01010010,01001010,01001001,00101001,00100101

23/64

00100101,00100101,00100101,00100101,00100101,00100101,00100101,00100101

24/64

00100101,00101001,01001001,01001010,01010010,10010010,10010100,10100101

25/64

00101001,01001010,01010010,10010101,00101001,01001010,01010010,10010101

26/64

00101001,01010010,10100101,00101010,01010100,10100101,01001010,10010101

27/64

00101010,01010101,00101010,01010101,00101010,01010101,00101010,01010101

28/64

00101010,10010101,01010010,10101010,01010101,01001010,10101001,01010101

29/64

00101010,10101010,01010101,01010101,00101010,10101010,01010101,01010101

30/64

00101010,10101010,10101010,10101010,01010101,01010101,01010101,01010101

31/64

01010101,01010101,01010101,01010101,01010101,01010101,01010101,01010101

32/64

01010101,01010101,01010101,01010101,10101010,10101010,10101010,10101011

31/64

33/64

01010101,01010101,10101010,10101011,01010101,01010101,10101010,10101011

30/64

34/64

01010101,01101010,10101101,01010101,10101010,10110101,01010110,10101011

29/64

35/64

01010101,10101011,01010101,10101011,01010101,10101011,01010101,10101011

28/64

36/64

01010110,10101101,01011010,11010101,10101011,01011010,10110101,01101011

27/64

37/64

01010110,10110101,10101101,01101011,01010110,10110101,10101101,01101011

26/64

38/64

01011010,11010110,10110110,10110101,10101101,01101101,01101011,01011011

25/64

39/64

01011011,01011011,01011011,01011011,01011011,01011011,01011011,01011011

24/64

40/64

01011011,01101011,01101101,10101101,10110101,10110110,11010110,11011011

23/64

41/64

01011011,01101101,10110110,11011011,01011011,01101101,10110110,11011011

22/64

42/64

01101101,10110110,11011011,01101101,10110110,11011011,01101101,10110111

21/64

43/64

01101101,10110111,01101101,10110111,01101101,10110111,01101101,10110111

20/64

44/64

01101101,11011011,01110110,11011101,10111011,01101110,11011011,10110111

19/64

45/64

01101110,11011101,10111011,01110111,01101110,11011101,10111011,01110111

18/64

46/64

01101110,11101110,11011101,11011101,10111011,10111011,01110111,01110111

17/64

47/64

01110111,01110111,01110111,01110111,01110111,01110111,01110111,01110111

16/64

48/64

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