AR0130CS

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12

Table 4. FRAME TIME (Example Based on 1280 x 960, 45 Frames Per Second)

Parameter

Timing at 74.25 MHz

Equation

Name

Frame valid time

Context A: ((R0x3006−R0x3002+1)*(A+Q))−Q+P1+P2

Context B: ((R0x3090−R0x308C+1)*(A+Q))−Q+P1+P2

1,583,642 pixel clocks

= 21.33 ms

F

Total frame time

V + (Nrows x (A + Q))

1,633,500 pixel clocks

= 22.22 ms

Sensor timing is shown in terms of pixel clock cycles (see

Figure 8). The recommended pixel clock frequency is

74.25 MHz. The vertical blanking and the total frame time

equations assume that the integration time (coarse

integration time plus fine integration time) is less than the

number of active lines plus the blanking lines:

WindowHeight ) VerticalBlanking

(eq. 1)

If this is not the case, the number of integration lines must

be used instead to determine the frame time, (see Table 5).

In this example, it is assumed that the coarse integration time

control is programmed with 2000 rows and the fine shutter

width total is zero.

For Master mode, if the integration time registers exceed

the total readout time, then the vertical blanking time is

internally extended automatically to adjust for the additional

integration time required. This extended value is not written

back

to

the

frame_length_lines

register.

The

frame_length_lines register can be used to adjust

frame−to−frame readout time. This register does not affect

the exposure time but it may extend the readout time.

Table 5. FRAME TIME: LONG INTEGRATION TIME

Parameter

Name

Equation

Timing at 74.25 MHz

F’

Total frame time (long

integration time)

Context A: (R0x3012 x (A + Q)) + R0x3014 + P1 + P2

Context B: (R0x3016 x (A + Q)) + V R0x3018 + P1 + P2

3,300,012 pixel clocks

= 44.44 ms

NOTE: The AR0130 uses column parallel analog−digital converters; thus short line timing is not possible. The minimum total line time is

1390 columns (horizontal width + horizontal blanking). The minimum horizontal blanking is 110.

Exposure

Total

integration

time

is

the

result

of

Coarse_Integration_Time

and

Fine_Integration_Time

registers, and depends also on whether manual or automatic

exposure is selected.

(eq. 1)

= (number of lines of integration x line time) − (410 pixel

clocks of conversion time overhead) − (number of pixels of

integration x pixel time)

where:

Control: Enabled)

When automatic exposure control (AEC) is enabled, the

number of lines of integration may vary from frame to

frame, with the limits controlled by R0x311E

(minimum auto exposure time) and R0x311C

(maximum auto exposure time).

Control: Disabled)

If AEC is disabled, the number of lines of integration

equals the value in R0x3012 (context A) or R0x3016

(context B).

The number of fine shutter width pixels is independent

of AEC mode (enabled or disabled):

equals the value in R0x3014.

equals the value in R0x3018.

Typically, the value of the Coarse_Integration_Time

register is limited to the number of lines per frame (which

includes vertical blanking lines), such that the frame rate is

not affected by the integration time. For more information

on coarse and fine integration time settings limits, please

refer to the Register Reference document.