Led screen display system scan board design thought

Led screen display system scan board design thought of data transmission control circuit scanning board input cascade data, in front 24bit standard conditions is the RGB grayscale value data. Each point scoring this point clock parallel 24bit data. So the data transmission control circuit of data input and output lines's best and 24 root, if not, it will be arrange data transmission format.

Scanning board is most concerned about which data belongs to own, to find these data method, of course, can use led display and control unit shift register solutions. In theory this is not a problem, but in circuit implementation is difficult, because in the display and control unit, need to lock to save data is small, but need latch scanning board of data a lot. Such as: in the adoption of 1/16 scanning mode, three colors every color, line 8bit 64 dot, a scanning board to latch 640x16x3x8 = 245760bit (30720byte). So much data, use latches is not realistic. Can use the more simple ways to solve data identifying problems. According to the given condition, can calculate every piece of scanning plate needed data quantity and the corresponding points clock. In the main controller that can signal generates a first, let this signal en width equal to a scan board the sum required points clock cycle. The main controller for the first piece of scanning the en board, first piece scanning the validity of board in en by some clock will data scored. En signal in various scanning board also cascade transmission between from a scan board, just another piece of scanning board to after delay, transmission time delay of time is equal to the width of En signal. So, the first piece of scanning board, second in en effectively ban state, with the passage of time sequence of along the cascade, each scanning board ordinal received en effective signal. Cooperate with the transmission data, each scanning plate can get that part of their own data.

This data control transmission method is very effective, it not only solved the problem of partition and intercept data, and in scanning board is too much control signal increase. Need to deal with the delay is en signal transmission. Actually to point by en signal count clock pulse can be directly obtained, delay time and down the surface league output signal is the en respectively for some clock counting of two results. Peacetime scanning board keep its en output is invalid, a when this scanning board input received en effective signal, it begins to point-to-point clock pulse, the counter to equivalent to count the number of points en width to cascade output, the subordinate send en effective signal and begin again again counted counts, when the equivalent of en width, make some clock en become invalid.

Using this method, need not consider scanning board positioning problem, because en signal is cascade transmission, a scanning board on cascade of a certain position, it will naturally intercepted belong to this position on display data, without other control intervention, can be done automatically.