4. Block decoder
* decode unit includes: IC 74LS74
- IC 74LS47 BCD decoder IC type of 7-segment LED. BCD decoder circuitry to 7 bar LED decoding circuit is complicated because the output circuit must for many high or low (depending on the type of LED is the anode or cathode 7 general bar) to make the light up to the port lacks the numbers characters. IC IC 74LS47 is kind of low impact has to open drain outputs and the ability to get high enough line to get high enough to flow directly form the common anode LEDs 7 bar.
- IC IC 74LS47 is a low impact should the level of output 1 is turned off, the light level 0, corresponding to the bars a, b, c, d, e, f, g of common anode led 7 bar type, status output, which corresponds to the number decimal.
- Input or RBI is to not connect to $ 1 used to remove the 0 (0 legacy behind decimal or 0 before the number means). When the RBI and inputs D, C, B, A at 0, input LT at 1, the outputs are switched off and the input ripple delete RBO low.
- Input BI is to not remove or connect to $ 1 for normal decoding operations. If connected to a 0, the outputs are disabled.
- When input BI / RBO level 1 and LT connectors at 0, the outputs are bright.
- The signal pulse generated by the pulse generator block is then put into counter for signal encoding and signal encryption then be transferred to the decoder for decoding for a signal after decoding.
5. Display Block
- Block displays the decoded signal received from the pins of the IC 74LS47 to show up after scrabble code signals.
- Block 7 bar LED display using common anode type output by IC 74LS47 had a positive as level 0 (low).
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