PXD20RM Datasheet, PDF (1566/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

Because ot the vertical scaling, a line buffer is used for each color component to store the data from
horizontal scaling, it stores one line of data. Size of the line buffer determines the maximum video output
size after scaling
The scaling factors are programmed via the HFACTOR (47.2.3.11/47-13) and VFACTOR
(47.2.3.12/47-13) registers. And video size after scaling is programmed via the VID_SIZE register
(47.2.3.13/47-14).
Three scalers are instantiated in the down-scaler block, one for each component.
NOTE
The scaled pixel count per line shall be integer multiply of 2 in 32-bit output
mode, or 4 in 16-bit output mode. The user shall divide the input pixel count
by the horizontal scaling factor and truncate the result to multiply of 2 or 4.
NOTE
To achieve good display quality, progressive video input shall be used if
down-scaling is needed.
47.3.5 Brightness and Contrast Adjust
The B/C Adjust block (4) performs brightness and contrast adjustment to the input video stream via three
internal look-up-tables, one table per color component. Each table contains 256 8-bit entries, it maps every
incoming pixel to the value of one of it’s entries according to the original value of the pixel. The
component is then replaced by the value in the table. If the incoming stream contains 10 bits per
component, then only the 8 most significant bits are mapped to the look-up table. This feature allows the
user to adjust brightness and/or contrast of the incoming picture according to three arbitrary adjustment
curves, one adjustment curve per color component.
To use this feature, the B/C adjust look-up-table shall be programmed in software in the following format.
47-18
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor