Basics of digital electronics

1. BASICS OF DIGITAL ELECTRONICS 1

2. 2 2 +1 =3 HOW THE COMPUTER GETS THE ANSWER

3. 3 A computer understands information composed of only zeros and ones. The decimal number system is convenient for the programmer. The computer uses binary digits for its operation. 1 1 1 1 1 1

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5. DECIMAL NUMBER SYSTEM 5

6. 6 DECIMAL NUMBER 4598 1 2 3

7. 7 BINARY NUMBER SYSTEM

8. 8 BINARY NUMBER 1011 1 2 3

9. 9 HEXADECIMAL NUMBER SYSTEM

10. 10 HEXADECIMAL NUMBER 1A5D 1 2 3

11. 11 OCTAL NUMBER SYSTEM

12. 12 OCTAL NUMBER 5273 1 2 3

13. 13 CONVERSIONS IN BASIC NUMBER SYSTEM

14. 14 BINARY TO DECIMAL 4 3 2 1

15. 15 HEXADECIMAL TO DECIMAL 2 1

16. 16 OCTAL TO DECIMAL 2 1

17. 17 DECIMAL TO BINARY L SB M SB Divide through out by 2 DECIMAL = 39 BINARY = 100111

18. 18 DECIMAL TO HEX Divide through out by 16 LSB MSB DECIMAL = 35 HEX = 23

19. 19 DECIMAL TO OCTAL D ivide through out by 8 LSB MSB DECIMAL = 461 OCTAL = 715

20. 20 BINARY TO HEXADECIMAL 2 16

21. 21 BINARY TO OCTAL 2 8

22. 22 HEXADECIMAL TO BINARY 16 2

23. 23 OCTAL TO BINARY 8 2

24. 24 HEXADECIMAL TO OCTAL 16 2 8

25. 25 OCTAL TO HEXADECIMAL 8 2 16

26. 26 REPRESENTATION OF NEGATIVE NUMBER

27. 27 BINARY ARITHMETIC

28. 28 0 + 0 = 0 1 + 0 = 1 0 + 1 = 1 1 + 1 = 0 1 (Carry bit) BINARY ADDITION 1 1 0 1 (13 decimal) +0 0 0 1 (+1 decimal) 1 1 1 0 (14 decimal)

29. 29 BINARY SUBTRACTION 0 ‐ 0 = 0 1 ‐ 0 = 1 0 ‐ 1 = 1 1 (Carry bit) 1 ‐ 1 = 0 1 1 0 1 (13 decimal) + 0 0 1 1 (-3 decimal) 1 0 1 0 (10 decimal) Borrow

30. 30 1 0 0 0 =8 10 X 0 1 1 0 =6 10 0 0 0 0 + 1 0 0 0 + 1 0 0 0 + 0 0 0 0 0 1 1 0 0 0 0 = 48 10 BINARY MULTIPLICATION

31. 31 BINARY DIVISION 011 ) 0 1 1 0 0 1 0 ( 1 0 1 1 0 0 0 (0 0 0 0 0 0 0 (0 0 0 0 0 0 1 (0 0 0 0 0 1 0 Q =1000=16 10 R= 10= 2 10

32. 32 SIGNED ARITHMETIC OPERATION MSB bit is reserved to represent the sign of the number. When the number is negative, the sign bit is kept one. When the number is positive, the sign bit is 0. In 8-bit processor, MSB = sign bit & other 7 bits = number. In 16-bit processor, MSB = sign bit & other 15 bits = number.

33. 33 EXAMPLES 0 0 0 0 0 1 0 1 (+5 decimal) 0 0 0 0 0 1 0 0 (+4 decimal) 0 0 0 0 1 0 0 1 (+9 decimal) 0 0 0 0 0 1 0 1 (+5 decimal) 1 0 0 0 0 0 1 0 (-2 decimal) 1 1 1 1 1 1 0 1 (1’comp of -2) 1 1 1 1 1 1 1 0 (2’s comp of -2) 0 0 0 0 0 0 1 1 (+3 decimal) 1 2 1 2 1

34. 34 BCD AND GRAY CODE

35. 35 LOGIC GATES Logic gates perform basic logical functions. They are fundamental building blocks of digital integrated circuits. Most logic gates take an input of two binary values, and output a single value of a 1 or 0. Some circuits may have only a few logic gates, while others, such as microprocessors, may have millions of them. There are seven different types of logic gates, which are outlined.

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43. 43 FLIP-FLOPS A flip-flop or latch is a circuit that has two stable states and can be used to store state information.  Each flip-flop stores one bit of information

44. 44 THANK YOU