On the board, one high quality video decoder (U100) is provided (VPC3230D of Micronas)
to process video inputs coming from the video sources. The video processor can process 3
composite video inputs and 1 S-Cideo input from the NTSC/PAL video sources. The CVBS
output recovered from the tuner module is made available to one of the video inputs of the
video decoder.
The digitized video output (in ITU-656 format) from U100 is fed to the dedicated video Port
of gm2221 for decoding and processing.
Gm2221 makes it possible to perform scaling and de-interlacing for the video input.
A 4Mbit serial flash ROM (U503) is used for storing system firmware. Also the footprint for
a parallel flash ROM, which can be upto 2Mbits, is available on the board. This option can
be used either for development or for production purposes.
The gm2221 provides direct connect via the integrated LVDS transmitters to LCD panels
with integrated LVDS receivers. Both single LVDS (via S503) and double LVDS(via S502)
panels can be supported directly from the L5-A main-board. For single LVDS panels, only
S503 connector is soldered on the main-board, which is a 20 pin connector. For Double
LVDS panels, only S502 connector is soldered on the main-board, which is a 30 pin
connector. For supporting different LVDS panels, different LVDS cables (either single or
double LVDS) can be made used.
For supporting different single or double TTL panels, a daughter board interface is used via
40 pin S506 connector. On this connector, the signals are 3x8bit RGB with TTL control
signals (i.e. HSync, VSync, CLK, O/E etc.) to support a wide variety of LCD panels.
Depending on the panel used, different daughter boards will be used to support that
particular panel. For single TTL panels, the daughter board will just be a routing the RGB
and control signals to the particular connector interface for that particular panel. For double
TTL panels, there will be two LVDS receiver IC’s on the daughter board (double TTL is not
directly from GM2221 but double LVDS is supporter due to IC packaging problems) to
demodulate double LVDS signal into double TTL signal.
The LCD panel resolution supported can be up to SXGA at 75 Hz or UXGA at 60 Hz.
It is important to note that at any point in time gm2221 could drive only one type of Panel.
When LVDS Panel is connected (to connector S503 or S502) ensure that the panel
backlight is connected to S508. The integrated PWM output from gm2221 is used to
control the LCD panel backlight intensity for dimming functions.
The on screen display is implemented using OSD capability of gm2221. Infra Remote (IR)
controller connector (S507) is provided as a primary control interface for connecting IR
detector to the GPIO of gm2221. An IR remote controller unit and detector provide remote
OSD menu access at user convenience.
