Kontron SMARC-sAT30 - Manual (Page 21)

User’s Guide
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3.2.9 Carrier Based 24 bit Color Depth LVDS
The Module parallel LCD path may be used to implement single or dual channel Carrier Board LVDS transmitter(s). The
color packing may be 24 bit or 18 bit. Since 18 bit single channel color packing is already available from the Module
LVDS, only 24 bit color packing is described in this section.
A single channel implementation uses one SN75LVDS83B (or equivalent) LVDS transmitter. A dual channel
implementation uses two transmitters – one for the odd pixels and one for the even pixels. The input to the two
transmitters is the same for both parts (they are wired in parallel). The odd and even pixels are separated out from the
input data by the rising and falling edges of the LCD_DUAL_PCK.
The following pins on the transmitter are used slightly differently in the single and dual channel cases:
Pixel Clock Input (Ball A2, Pin Name CLKIN) For single channel implementations, connect to the SMARC
LCD_PCK pin (S123)
For dual channel implementations, connect to the SMARC
LCD_DUAL_PCK pin (S142)
Clock Edge Select (Ball D4, Pin Name CLKSEL) For single channel implementations: provide for resistor strapping
options to tie this high or low. The default strapping should be
low, which sets the TI LVDS transmitter to latch data in on the
falling edge of the LCD_PCK.
For dual channel implementations, provide for strapping options
to tie the CLKSEL pins high or low. The two transmitters should
have separate strapping options (or one set of strapping options
and an inverter to set the CLKSEL pin on the 2 nd transmitter to the
opposite edge). The first transmitter, for odd pixels, should be set
to latch the data on the rising edge of LCD_DUAL_PCK. The second
transmitter, for even pixels, should be set to latch the data on the
falling edge of the LCD_DUAL_PCK.
The following table shows how the sAT30 LCD pins should be mapped to a particular LVDS transmitter, the TI
SN75LVDS83B, for standard LVDS 24 bit color packing, single and dual channel. The chart shows pin numbers for the
BGA version of the part. The TSSOP version can be used as well, although the pin numbering is different. The pin names
remain the same. Transmitters from other vendors may be used as well. For dual channel implementations, the same
data path pin mapping is used for both channels (i.e. the LVDS transmitter LCD parallel data inputs are to be connected
in parallel).