Silicon Imaging SI-3300 MegaCamera, Instruction Manual

Page: 22 / 39

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Silicon Imaging , Inc. 2004 Page 22 of 39 Company Confidential
GAIN CONTROL (Registers: 2B , 2C , 2D , 2E , 35)
The SI-3300 contains manual Analog and Digital gain controls for each color channel (G1, G2, R, B). Analog Gain
values may be set using the following registers: G1 = 0x2B [6..0], G2 = 0x2E [6..0], R = 0x2D [6..0], and B = 0x2C
[6..0]. In addition, the SI3300 contains a global gain register, 0x35 [6..0], that applies the gain value to all gain
channels (G1, G2, R ,B ). Digital Gains are set using Bits{14~8] of each of the registers. The total gain = analog
gain x digital gain. When the global gain register (Reg35) is read, it returns only the gain setting from the Green 1
channel register 0x2B.
0x2B Green1 Gain
0x0008 (8)
1x gain.
0x2C Blue Gain
0x0008 (8)
1x gain.
0x2D Red Gain
0x0008 (8)
1x gain.
0x2E Green2 Gain
0x0008 (8)
1x gain.
Gain Increments Settings :
1.000 to 4.000 0.125 0x0008 to 0x0020
4.25 to 8.00 0.25 0x0051 to 0x0060
9.0 to 18.0 1.0 0x0160 to 0x7860
Bits 6~0 : Analog Gain = (Bit[6] + 1) x Bit[5-0] x 0.125)
Bits 14~8: Digital Gain = 1 + Bit[14-8] / 8
Total Gain = Analog x Digital Gain
0x35 Global Gain
0x0008 (8)
1x gain.
This register can be used to set all four gains at once.
When read, it will return the value stored in Reg0x2B.
The table below shows recommended gain register settings and corresponding gain values:
Register Setting (0x2B,
0x2C, 0x2D, 0x2E, 0x35)
Gain
Register Setting (0x2B,
0x2C, 0x2D, 0x2E, 0x35)
Gain
Decimal Hex Gain Gain [dB] Decimal Hex Gain Gain [dB]
8 0x08 1 0 32 0x20 4 12.0
9 0x09 1.125 1.0 81 0x51 4.25 12.6
10 0x0A 1.25 1.9 82 0x52 4.5 13.1
11 0x0B 1.375 2.8 83 0x53 4.75 13.5
12 0x0C 1.5 3.5 84 0x54 5 14.0
13 0X0D 1.625 4.2 85 0x55 5.25 14.4
14 0x0E 1.75 4.9 86 0x56 5.5 14.8
15 0x0F 1.875 5.5 87 0x57 5.75 15.2
16 0x10 2 6.0 88 0x58 6 15.6
17 0x11 2.125 6.5 89 0x59 6.25 15.9
18 0x12 2.25 7.0 90 0x5A 6.5 16.3
19 0x13 2.375 7.5 91 0x5B 6.75 16.6
20 0x14 2.5 8.0 92 0x5C 7 16.9
21 0x15 2.625 8.4 93 0x5D 7.25 17.2
22 0x16 2.75 8.8 94 0x5E 7.5 17.5
23 0x17 2.875 9.2 95 0x5F 7.75 17.8
24 0x18 3 9.5 96 0x60 8 18.1
25 0x19 3.125 9.9 352 0x160 9 19.1
26 0x1A 3.25 10.2 353 0x161 10 20.0
27 0x1B 3.375 10.6 354 0x162 11 20.8
28 0x1C 3.5 10.9 355 0x163 12 21.6
29 0x1D 3.625 11.2
356 0x164 13 22.3
30 0x1E 3.75 11.5
357 0x165 14 22.9
31 0x1F 3.875 11.8 358 0x166 15 23.5