The DDS1139-01 electronic board is essentially a 16x16 RGB LED matrix panel (256 LEDs): the nominal dimensions are 247 x 247mm while the pitch of the LEDs is 15.94mm.
The implementation is based on the MBI6023 chip: in total there are 64 MBI each of which drives 4 RGB LEDs (i.e. 12 R+G+B primary emitters).
The image pixel is in 1:1 correspondence with an RGB LED.
The data communication interface is based on a single SPI bus where each MBI receives the clock and data signals and repeats them regenerated for the following MBI: at the end of the chain, the signals are eventually available to connect several DDS1139-cards in sequence 01. The transmission protocol is MBI proprietary.