MB86294 Datasheet, PDF (73/305 Pages) Fujitsu Component Limited. – Grraphiics Controller specifications

FUJITSU LIMITED
PRELIMINARY and CONFIDENTIAL
7.3 S c a l i n g
7.3.1 Video Reduction 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
Reduction in horizontal direction
576 → 490 lines
1.176×2048=2408
720 → 648 pixels
1.111×2048=2275
576/490 = 1.176
→ 0968H
720/648 = 1.111
→ 08E3H
Therefore, 096808E3H is set in CSC.
The capture horizontal pixel register (CHP) and capture vertical pixel register (CVP) are used to limit the
number of pixels processed during scaling. They are not used to set scaling values. Clamp processing
is performed on the video streaming data outside the values set in CHP and CVP. Usually, the defaults
for these registers are used.
7.3.2 Vertical Interpolation
When the VI bit of the video capture mode register (VCM) is “0”, data in the same field is used to
interpolate the interlace screen vertically. The interlace screen is doubled in the vertical direction.
When the VI bit is “1”, the interlace screen is not interpolated vertically.
7.4 E r r o r H a n d l i n g
7.4.1 Error Detection Function
If an expected control code is not detected in the input video stream, an error occurs. If an error occurs,
the status is returned to the register.
MB86294/294S CORAL_LB
Graphics Controller
73
Specifications Rev. 1.0