lm9617 National Semiconductor Corporation, lm9617 Datasheet - Page 11

• Manufacturer Part Number: lm9617
• Description: Monochrome Cmos Image Sensor Vga 30 Fps
• Manufacturer: National Semiconductor Corporation

Functional Description
2.0
The integrated timing and control circuit allows any size window
in any position within the active region of the array to be read out
with a 1x1 pixel resolution. The window read out is called the
“Display Window”.
A “Scan Window” must be defined first, by programing the start
and end row addresses as shown in Figure 13. Four coordinates
(start row address, start column address, end row address &
end column address) are programmed to define the size and
location of the “Display Window” to be read out (see Figure 13).
Notes:
• The “Display Window” must always be defined within the
• A “Display Window” can only be read out in the progressive
• By default the “Display Window” is the complete array.
2.1
Two registers (SROWS & SROWE) are provided to program the
size of the scan window. The start and end row address of the
scan window is given by:
Where:
2.2
Five register (DROWS, DROWE, DCOLS, DCOLE and DWLSB)
are provided to program the display window as described in the
register section of this datasheet.
3.0
3.1
In progressive scan readout mode, every pixel in every row in
the display window is consecutively read out, one pixel at a time,
starting with the left most pixel in the top most row. Hence, for
the example shown in Figure 13, the read out order will be
a0,b0,...,r0 then a1,b1,...,r1 and so on until pixel r20 is read out.
Confidential
end address
start address
end address
display row
display row
“Scan Window”.
scan mode.
scan row
start address
scan row start address = (2* SwStartRow) + SwLsb
scan row end address = (2* SwEndRow) + 1 + SwLsb
SwStartRow
SwEndROW
SwLsb
scan row
WINDOWING
Programming the scan window
Programming the display window
READ OUT MODES
Progressive Scan Readout Mode
is the contents of the Scan Window start row
register (SROWS)
is the contents of the Scan Window end row reg-
ister (SROWE)
is bit 6 of the Display Window LSB register
(DWLSB)
Figure 13. Windowing
start address
display col
Display Window
(continued)
Active Pixel Array
end address
display col
Scan Window
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3.2
In interlaced readout mode, pixels are read out in two fields, an
Odd Field followed by an Even Field.
The Odd Field, consisting of all even rows contained within the
display window, is read out first. Each pixel in the “Odd Field” is
consecutively read out, one pixel at a time, starting with the left
most pixel in the top most even row.
The Even Field, consisting of all odd rows contained within the
display window, is then read out. Each pixel in the “Even Field”
is consecutively read out, one pixel at a time, starting with the
left most pixel in the top most odd row.
Hence, for the example shown in Figure , the display window is
broken up into two fields, as shown in Figure . Pixels a0,b0,...,r0
followed by a2,b2,...,r2 and so on until pixels a20,b20,...r20 in
the even field are read out first. The even field read out is fol-
lowed by pixels in the odd field, a1,b1,...,r1 then a3,b3,...,r3 until
pixels a19,b19,...,r19.
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20
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1
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Interlaced Readout Mode
Figure 14: Progressive Scan Read Out Mode
a b c d e f g h i j k l m n o p q r
a b c d e f g h i j k l m n o p q r
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Figure 15: Interlace Read Out Mode
a b c d e f g h i j k l m n o p q r
Column/Horizontal
Column/Horizontal
Odd Field
Even Field
Column/Horizontal
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