m. Binary to Base 10 Decoder Lesson

m. Binary to Base 10 Decoder Lesson - 1COMPUTER ENGINEERING

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Unformatted text preview: 1COMPUTER ENGINEERING Name:________________________ Binary to Base 10 Decoder Purpose: Theory: To translate or decode a binary (base 2) input to a base 10 output Digital computers deal with on (1) and off (0). The 74LS47 chip will translate a binary input into signals to a seven-segment display. The seven-segment display will produce any single digit from 0 through 9 . The chip schematic is shown below. Specification Website: ht Procedure: 1. Carefully insert the 7-segment display so that it straddles the centre groove of the breadboard. 2. Connect a 330 Ω resistor from pin 14 and pin 3 to D0 on the parallel port. Connecting pin 3 & 14 directly to +5v will damage the seven-segment display. One resistor should serve both pins. 3. Use the diagram below and on the next page to wire the circuit. Note: On the 74LS47 decoder chip A B C D Pin 7 goes to D1 Pin 1 goes to D2 Pin 2 goes to D3 Pin 6 goes to D4 Pin 16 goes to D5 Pin 8 goes to ground Results: Complete the truth table by using. parallelput ( ) delay (3000) parallelput (0) A 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 Display 0 1 2 3 4 5 6 7 8 9 Binary Number 1 3 5 7 9 11 13 15 17 19 D 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 C 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 B 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 Conclusions: (Answer these questions in sentence form before submitting it for marking.) 1. Why must four inputs (A, B, C and D ) be used to display the digits 0 through 9? In order to reach the maximum binary digit that could be displayed by the seven-segment display (9) four digits are required: 1 0 0 1. 2. Connect pin 4 on the 74LS47 decoder chip to ground. What happens? (This pin is often called the blanking input pin). The whole display turns OFF. 3. Where might this feature be used in other electronic applications? In any application that would involve resetting the whole circuit. 4. What happens when you connect pin 3 on the 74LS47 decoder chip to ground? The display turns all ON (with the exception of the db lights). 5. Where might this feature be used in other electronic applications? In any application that would involve testing to see if the lights works properly. 6. Why do digital computers require coding and decoding chips? In order to make the human-computer interaction more accessible, we have to constantly decrypt the binary code into the decimal code for the humans to understand and then the instructions have to be encoded back into the binary in order for the computer to understand it. 7. Write a program that displays 0 to 9 and back from 9 to 0 three times. (Add a delay so that you can see the numbers .) Hint: Use a loop in your program. var count : int := 0 loop for x : 0..9 parallelput(x) delay(1000) end for delay(2000) for decreasing y : 9..0 parallelput(y) delay(1000) end for count = count + 1 if count = 3 then exit end if end loop 8. Write a program that displays 0,2,4,6,8 then 9,7,5,3,1 two times. var count : int := 0 loop for x : 0..8 by 2 parallelput(x) delay(1000) end for delay(2000) for decreasing y : 9..1 by 2 parallelput(y) delay(1000) end for count = count + 1 if count = 2 then exit end if end loop ...
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This note was uploaded on 02/10/2011 for the course ICE 4M1 taught by Professor Deabr during the Spring '11 term at Spring Arbor University.

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