MB86296 Datasheet, PDF (90/352 Pages) Fujitsu Component Limited. – PCI Graphics Controller Specification

FUJITSU LIMITED PRELIMINARY AND CONFIDENTIAL
8.3 Scaling
8.3.1 Down-scaling Function
When the CM bits of the video capture mode register (VCM) are 11, Coral reduces the video
screen size. The reduction can be set independently in the vertical and horizontal scales. The
reduction is set per line in the vertical direction and in 2-pixel units in the horizontal direction. The
scale setting value is defined by an input/output value. It is a 16-bit fixed fraction where the integer
is represented by 5 bits and the fraction is represented by 11 bits. Valid setting values are from
0800H to FFFFH. Set the vertical direction at bit 31 to bit 16 of the capture scale register (CSC) and
the horizontal direction at bits 15 to bit 00. The initial value for this register is 08000800H (once).
An example of the expressions for setting a reduction in the vertical and horizontal directions is
shown below.
Reduction in vertical direction
576 -> 490 lines
576/490 = 1.176
1.176×2048=2408
-> 0968H
Reduction in horizontal direction 720 -> 648 pixels
720/648 = 1.111
1.111×2048=2275
-> 08E3H
Therefore, 096808E3H is set in CSC.
The capture horizontal pixel register (CHP) is used to limit the number of pixels processed during
scaling. It is not used to set scaling values. Clamp processing is performed on the video streaming
data outside the values set in CHP. Usually, the defaults for these registers are used.
8.3.2 Up-scaling Function
Coral is able to enlarge the size of a video capture picture by the factor of 2 in both the horizontal
and vertical directions. This feature can be used to realize full-screen modes of video input streams
which have a resolution less than actual display size. In order to use magnify (up-scaling) mode,
the horizontal and vertical factor must be less than one. Do initialize the following registers as
follows :
Set the magnify flag in the L1-layer mode register of the display controller.
Set the picture source size (before magnification) into CMSHP and CMSVL.
Set the final picture size (after magnification) into CMDHP and CMDVL.
An example of the expressions for setting an enlargement in the vertical and horizontal directions is
shown below :
If the input picture size is 480x360 and the display picture size is 640x480, then the parameters for
each register are as follows.
HSCALE=(480/640)*2048=0x0600
VSCALE=(360/480)*2048=0x0600
CMSHP=0x00f0
CMSVL=0x0168
CMDHP=0x0140
CMDVL=0x01e0
L1WW=0x0280
L1WH=0x01df
MB86296S<Coral-PA>
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Specification Manual Rev0.1