SAA8112HL Datasheet, PDF (16/40 Pages) NXP Semiconductors – Digital camera signal processor and microcontroller

Philips Semiconductors
Digital camera signal processor and
microcontroller
Product specification
SAA8112HL
8.7 Measurement Engine
The ME extracts statistical information from the video
stream. These measurements are used to automatically
control the white balance and the exposure. They can also
be used for other purposes, such as colour detection.
The measurements are performed on pre-formatted
Y, U and V streams (see Fig.5). It is possible to measure
the accumulated value of the Y, U or V samples in any of
16 programmable windows. It is also possible to measure
the accumulated value of the Y signal below a threshold or
the number of Y samples above a threshold. Moreover, it
is possible to only accumulate U and V values for which
programmable conditions on Y, U and V are fulfilled.
The ME does up to 16 statistic measurements per frame
(8 per field). Each measurement can be done on any of the
pre-formatted signals and on any of the programmable
windows.
A memory area of the SAA8112HL, called RAM
workspace, is used to handle the ME operations.
In addition to the ME, a highlight counter is available,
which counts the number of pixels above a programmable
threshold. The highlight counter is usually used for
exposure control.
8.8 Display features
The SAA8112HL also offers the possibility of visualizing
selected zones of interests or selected pixels.
The visualization is done either by contrast reduction for
the selected pixels or by constant level insertion.
handbook, full pagewidth
CCD9 to CCD0
SAA8112HL
PROCESSING
YAWB UAWB VAWB YAE
MEASUREMENT ENGINE
ACCUMULATOR A
ACCUMULATOR B
YUV output
RAM WORKSPACE
SNERT INTERFACE
FCE345
Microcontroller (80C51)
2000 Jan 18
Fig.8 Measurement Engine.
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