unit n1

1. 1
ComputerComputer ArchitectureArchitecture
andand
MicroprocessorMicroprocessor
Dr. V.Umadevi M.Sc(CS &IT). M.Tech (IT)., M.Phil., PhD., D.Litt.,Dr. V.Umadevi M.Sc(CS &IT). M.Tech (IT)., M.Phil., PhD., D.Litt.,
Director, Department of Computer Science, Jairams Arts andDirector, Department of Computer Science, Jairams Arts and
Science College, KarurScience College, Karur

2. Computer Architecture
& Microprocessor
22
Session ISession I
 Number SystemNumber System
 ConversionsConversions
 Binary OperationsBinary Operations
 CodeCode
 Logic GatesLogic Gates
 Boolean AlgebraBoolean Algebra
 Registers & CountersRegisters & Counters
 Computer LanguagesComputer Languages

3. Computer Architecture
& Microprocessor
33
Number SystemNumber System
Systematic representation of data in Numerical FormatSystematic representation of data in Numerical Format
 Decimal Number SystemDecimal Number System  0 to 90 to 9
 Binary Number SystemBinary Number System  0 and 10 and 1
 Octal Number SystemOctal Number System  0 to 70 to 7
 Hexa Decimal Number SystemHexa Decimal Number System  0 to 9 and A to F0 to 9 and A to F

4. Computer Architecture
& Microprocessor
44
Decimal Number SystemDecimal Number System
 Uses digits from 0 to 9.Uses digits from 0 to 9.
 Has a base of 10Has a base of 10
 Value of digit corresponds to its position in the numberValue of digit corresponds to its position in the number
number X (base)number X (base)position-1position-1
 Example :Example :
4954951010 , 84, 841010

5. Computer Architecture
& Microprocessor
55
Binary Number SystemBinary Number System
 Computer uses the Binary Number SystemComputer uses the Binary Number System
 Consists of numbers 0 and 1Consists of numbers 0 and 1
 Bit (Bit (BBinary diginary digitit))
 Byte (8 - bits)Byte (8 - bits)
 Example:Example:
1010101022 , 1110, 111022

6. Computer Architecture
& Microprocessor
66
Octal Number SystemOctal Number System
 Uses the digits from 0 to 7.Uses the digits from 0 to 7.
 Has a base of 8Has a base of 8
 can be represented by a group of 3 bitscan be represented by a group of 3 bits
 Example:Example:
12312388 , 435, 43588

7. Computer Architecture
& Microprocessor
77
Hexa Decimal Number SystemHexa Decimal Number System
 Uses the digits from 0 to 15.Uses the digits from 0 to 15.
 Numbers from 10 to 15 represented by alphabets A through FNumbers from 10 to 15 represented by alphabets A through F
 Has a base of 16Has a base of 16
 Can be represented by a group of 4 bits.Can be represented by a group of 4 bits.
 Example:Example:
B3A1B3A11616 , 98C, 98C1616

8. Computer Architecture
& Microprocessor
88
Number System TableNumber System Table
DecimalDecimal
NumberNumber
SystemSystem
BinaryBinary
NumberNumber
SystemSystem
Octal NumberOctal Number
SystemSystem
Hexa DecimalHexa Decimal
NumberNumber
SystemSystem
00
11
22
33
44
55
66
77
88
99
1010
1111
1212
1313
1414
1515
00000000
00010001
00100010
00110011
01000100
01010101
01100110
01110111
10001000
10011001
10101010
10111011
11001100
11011101
11101110
11111111
00
11
22
33
44
55
66
77
1010
1111
1212
1313
1414
1515
1616
1717
00
11
22
33
44
55
66
77
88
99
AA
BB
CC
DD
EE
FF

9. Computer Architecture
& Microprocessor
99
Conversion of decimal Number to Hexadecimal NumberConversion of decimal Number to Hexadecimal Number
 To convert, divide the decimal number by 16 successivelyTo convert, divide the decimal number by 16 successively
ExampleExample
To convert 540 to decimalTo convert 540 to decimal
16 54016 540
16 33 -1216 33 -12
2 - 12 - 1
The decimal equivalent of 540The decimal equivalent of 5401010 = 21C= 21C1616

10. Computer Architecture
& Microprocessor
1010
Conversion from Hexadecimal to DecimalConversion from Hexadecimal to Decimal
 Multiply the digits of the number by the powers of 16 and addMultiply the digits of the number by the powers of 16 and add
ExampleExample
 To convert 21CTo convert 21C1616 to its decimal equivalentto its decimal equivalent
2 1 C
C X160
= 12 X 1 = 12
1 X161
= 1 X 16 = 16
2 X162
= 2 X 256= 512
540

11. Computer Architecture
& Microprocessor
1111
Conversion of Hexadecimal to Binary NumberConversion of Hexadecimal to Binary Number
 The binary equivalent of each digit is usedThe binary equivalent of each digit is used
ExampleExample
 To convert 5BTo convert 5B1616 to binary equivalent:to binary equivalent:
5 B5 B
010110110101101122
 To convert B316 to binary equivalent:To convert B316 to binary equivalent:
B 3B 3
101100111011001122

12. Computer Architecture
& Microprocessor
1212
Conversion of Binary to Decimal NumberConversion of Binary to Decimal Number
 Sum of product of each digit with 2 raised to the powerSum of product of each digit with 2 raised to the power
of positional valueof positional value
Example:Example:
To find the decimal equivalent of 1011To find the decimal equivalent of 101122 ::

13. Computer Architecture
& Microprocessor
1313
Conversion from Octal to DecimalConversion from Octal to Decimal
 Multiply the digits of the number by the powers of 8 and addMultiply the digits of the number by the powers of 8 and add
ExampleExample
 To convert 215To convert 21588 to its decimal equivalentto its decimal equivalent
2 1 5
5 X 80
= 5 X 1 = 5
1 X 81
= 1 X 8 = 8
2 X 82
= 2 X 64= 128
141

14. Computer Architecture
& Microprocessor
1414
9’s Complement9’s Complement
 Difference of each digit of a number from 9Difference of each digit of a number from 9
Example:Example:
 To find 9’s complement ofTo find 9’s complement of 5454 ::
9 99 9
5 45 4
4 54 5

15. Computer Architecture
& Microprocessor
1515
10’s Complement10’s Complement
 Equivalent to the negative of a numberEquivalent to the negative of a number
 Obtained by adding 1 to the 9’s complement of a numberObtained by adding 1 to the 9’s complement of a number
Example:Example:
 To find 10’s complement of 54To find 10’s complement of 54
= 9’s complement of 54 + 1= 9’s complement of 54 + 1
= 45 + 1= 45 + 1
== 4646

16. Computer Architecture
& Microprocessor
1616
1’s Complement of binary number1’s Complement of binary number
 Similar to 9’s complement of decimal numberSimilar to 9’s complement of decimal number
 Obtained by subtracting each digit from 1Obtained by subtracting each digit from 1
ExampleExample
 To find 1’s complement of 101To find 1’s complement of 101
1 1 11 1 1
1 0 11 0 1
0 1 00 1 0

17. Computer Architecture
& Microprocessor
1717
2’s complement of a binary number2’s complement of a binary number
 Equivalent to 10’s complement of a decimal numberEquivalent to 10’s complement of a decimal number
 Represents the negative equivalent of that numberRepresents the negative equivalent of that number
ExampleExample
 To find the 2’s complement of 1010To find the 2’s complement of 1010
= 1’s complement of 1010 + 1= 1’s complement of 1010 + 1
= 0101 + 1= 0101 + 1
== 01100110

18. Computer Architecture
& Microprocessor
1818
Binary SubtractionBinary Subtraction
To subtractTo subtract 10101010 fromfrom 11001100
 Find 2’s complement of 1010Find 2’s complement of 1010
NumberNumber : 1010: 1010
1’s complement1’s complement : 0101: 0101
2’s complement2’s complement : 0110: 0110
 Add 2’s complement of 1010 with 1100Add 2’s complement of 1010 with 1100
11001100
01100110
00100010

19. Computer Architecture
& Microprocessor
1919
BCDBCD
 Each digit is represented by four bitsEach digit is represented by four bits
Decimal NumberDecimal Number BCDBCD
88 0000100000001000
99 0000100100001001
1010 0001000000010000
1111 0001000100010001
1212 0001001000010010
1313 0001001100010011
1414 0001010000010100
1515 0001010100010101
Decimal NumberDecimal Number BCDBCD
00 00000000
11 00010001
22 00100010
33 00110011
44 01000100
55 01010101
66 01100110
77 01110111

20. Computer Architecture
& Microprocessor
2020
Gray CodeGray Code
 Only one bit changes for each consecutive numbersOnly one bit changes for each consecutive numbers
Decimal NumberDecimal Number Gray CodeGray Code
88 11001100
99 11011101
1010 11111111
1111 11101110
1212 10101010
1313 10111011
1414 10011001
1515 10001000
Decimal NumberDecimal Number Gray CodeGray Code
00 00000000
11 00010001
22 00110011
33 00100010
44 01100110
55 01110111
66 01010101
77 01000100

21. Computer Architecture
& Microprocessor
2121
ASCII CodesASCII Codes
 American Standard Code for Information InterchangeAmerican Standard Code for Information Interchange
 7 bit code7 bit code
 Represents upto 128 charactersRepresents upto 128 characters
 First 3 bits-zone bitsFirst 3 bits-zone bits
 Second 4 bits-numeric bitsSecond 4 bits-numeric bits

22. Computer Architecture
& Microprocessor
2222
ASCII CodesASCII Codes
ASCII Code Character
00 NUL
01 SOH
02 STX
03 ETX
04 EOT
05 ENQ
06 ACK
07 BEL
08 BS
09 HT
0A LF
0B VT
0C FF
0D CR
0E S1
0F S0
10 DLE
ASCII Code Character
11 DC1 (X-on)
12 DC2 (Tape)
13 DC3 (X-off)
14 DC4
15 NAK
16 SYN
17 ETB
18 CAN
19 EM
1A SUB
1B ESC
1C FS
1D GS
1E RS
1F US
20 SP
21 !

23. Computer Architecture
& Microprocessor
2323
ASCII CodeASCII Code
ASCII Code Character
22 “
23 #
24 $
25 %
26 &
27 ‘
28 (
29 )
2A *
2B +
2C ,
2D -
2E .
2F /
30 0
31 1
ASCII Code Character
32 2
33 3
34 4
35 5
36 6
37 7
38 8
39 9
3A :
3B ;
3C <
3D =
3E >
3F ?
40 @
41 A

24. Computer Architecture
& Microprocessor
2424
ASCII Code Character
42 B
43 C
44 D
45 E
46 F
47 G
48 H
49 I
4A J
4B K
4C L
4D M
4E N
4F O
50 P
51 Q
52 R
53 S
54 T
55 U
ASCII Characters
56 V
57 W
58 X
59 Y
5A Z
5B [
5C
5D ]
5E ^ ( )
5F - ( )
61 a
62 b
63 c
64 d
65 e
66 f
67 g
69 h
6A i
6B j

25. Computer Architecture
& Microprocessor
2525
ASCII Code Character
6B k
6C l
6D m
6E n
6F o
70 p
71 q
72 r
73 s
74 t
75 u
76 v
77 w
78 x
79 y
7A z
7B {
7C |
7D }
7E ~
7F DEL

26. Computer Architecture
& Microprocessor
2626
ASCII -8 CodeASCII -8 Code
 Uses 8 bit codeUses 8 bit code
 Represents upto 256 charactersRepresents upto 256 characters
 First 4 bits-zone bitsFirst 4 bits-zone bits
 Second 4 bits-numeric bitsSecond 4 bits-numeric bits

27. Computer Architecture
& Microprocessor
2727
Logic GatesLogic Gates
NOT gateNOT gate or Inverteror Inverter
 output is opposite of inputoutput is opposite of input
 Truth TableTruth Table
I/P 0/PI/P 0/P
0 10 1
1 01 0
I/P O/P

28. Computer Architecture
& Microprocessor
2828
AND GateAND Gate
Truth TableTruth Table
I/P1I/P1 I/P2I/P2 O/PO/P
00 00 00
00 11 00
11 00 00
11 11 11
I/P1
I/P2
O/P

29. Computer Architecture
& Microprocessor
2929
NAND GateNAND Gate
Truth TableTruth Table
I/P1I/P1 I/P2I/P2 O/PO/P
00 00 11
00 11 11
11 00 11
11 11 00
I/P1
I/P2
O/P

30. Computer Architecture
& Microprocessor
3030
OR GateOR Gate
Truth TableTruth Table
I/P1I/P1 I/P2I/P2 O/PO/P
00 00 00
00 11 11
11 00 11
11 11 11
I/P1
I/P2
O/P

31. Computer Architecture
& Microprocessor
3131
NOR GateNOR Gate
Truth TableTruth Table
I/P1I/P1 I/P2I/P2 O/PO/P
00 00 11
00 11 00
11 00 00
11 11 00
I/P1
I/P2
O/P

32. Computer Architecture
& Microprocessor
3232
XOR GateXOR Gate
Truth TableTruth Table
I/P1I/P1 I/P2I/P2 O/PO/P
00 00 00
00 11 11
11 00 11
11 11 00
I/P1
I/P2
O/P

33. Computer Architecture
& Microprocessor
3333
XNOR GateXNOR Gate
Truth TableTruth Table
I/P1I/P1 I/P2I/P2 O/PO/P
00 00 11
00 11 00
11 00 00
11 11 11
I/P1
I/P2
O/P

34. Computer Architecture
& Microprocessor
3434
Boolean AlgebraBoolean Algebra
 Algebra of binary values(1 & 0)Algebra of binary values(1 & 0)
 Types of operationsTypes of operations
 OR (+)OR (+)
 AND ( . )AND ( . )
 NOT (- or ‘ )NOT (- or ‘ )
 Minimizes the basic circuits to perform digital operationsMinimizes the basic circuits to perform digital operations

35. Computer Architecture
& Microprocessor
3535
Algebraic TheoremsAlgebraic Theorems
OR LawsOR Laws
• A + 0 = AA + 0 = A
• A + 1 =1A + 1 =1
• A + A = AA + A = A
• A + A = 1A + A = 1
AND LawsAND Laws
• A . 0 = 0A . 0 = 0
• A . 1 = AA . 1 = A
• A . A = AA . A = A
• A . A = 0A . A = 0

36. Computer Architecture
& Microprocessor
3636
Laws of ComplementationLaws of Complementation
 A = AA = A
 1 = 01 = 0
 0 = 10 = 1
 If A=0, then A =1If A=0, then A =1
 If A=1, then A = 0If A=1, then A = 0
Commutative LawsCommutative Laws
 A + B = B + AA + B = B + A
 A .B = B .AA .B = B .A
Associative LawsAssociative Laws
 (A + B) + C = A + (B + C) = A + B + C(A + B) + C = A + (B + C) = A + B + C
 (A.B).C = A.(B.C) = A.B.C(A.B).C = A.(B.C) = A.B.C

37. Computer Architecture
& Microprocessor
3737
Distributive LawsDistributive Laws
 A . (B+C) = A .B + A .CA . (B+C) = A .B + A .C
 A + B.C = (A + B) . (A + C)A + B.C = (A + B) . (A + C)
Other ExpressionsOther Expressions
 A + AB = AA + AB = A
 A . (A + B) = AA . (A + B) = A
 A + AB = A + BA + AB = A + B
 A . (A + B) = ABA . (A + B) = AB
 AB + AB = AAB + AB = A
 (A + B)(A + B) = A(A + B)(A + B) = A
 AB + AC = (A + C) . (A + B)AB + AC = (A + C) . (A + B)
 (A + B) ( A + C) = AC + AB(A + B) ( A + C) = AC + AB
 AB + AC + BC = AB + ACAB + AC + BC = AB + AC
 (A + B)(A + C)(B + C) = (A + B)(A + C)(A + B)(A + C)(B + C) = (A + B)(A + C)

38. Computer Architecture
& Microprocessor
3838
Half Adder
Has two inputs (the bits to be summed)
Has two outputs (the sum bit and the carry bit)
AB CD
00
01
10
11
00
10
10
01

39. Computer Architecture
& Microprocessor
3939
an
bn
cn
sn
cn+1
0 0 0 0 0
0 0 1 1 0
0 1 0 1 0
0 1 1 0 1
1 0 0 1 0
1 0 1 0 1
1 1 0 0 1
1 1 1 1 1
Full Adder – Truth Table

40. Computer Architecture
& Microprocessor
4040
7 Segment LED Display

41. Computer Architecture
& Microprocessor
4141

42. Computer Architecture
& Microprocessor
4242
0 0 0 0 0
1 0 0 0 1
2 0 0 1 0
3 0 0 1 1
4 0 1 0 0
5 0 1 0 1
6 0 1 1 0
7 0 1 1 1
8 1 0 0 0
9 1 0 0 1
1 1 1 1 1 1 0
0 1 1 0 0 0 0
1 1 0 1 1 0 1
1 1 1 1 0 0 1
0 1 1 0 0 1 1
1 0 1 1 0 1 1
1 0 1 1 1 1 1
1 1 1 0 0 0 0
1 1 1 1 1 1 1
1 1 1 1 0 1 1
INPUTS
X Y Z W A B C D E F G
OUTPUT
L
E
G
A
L
D
I
G
I
T
S
1 0 1 0
1 0 1 1
1 1 0 0
1 1 0 1
1 1 1 0
1 1 1 1
1 0 0 1 1 1 1
1 0 0 1 1 1 1
1 0 0 1 1 1 1
1 0 0 1 1 1 1
1 0 0 1 1 1 1
1 0 0 1 1 1 1
E
R
R
O
R
7 Segment LED Display– Truth Table

43. Computer Architecture
& Microprocessor
4343
TTL CircuitTTL Circuit
 Stands for transistor - transistor logic.Stands for transistor - transistor logic.

Operates between cut-off and saturation.Operates between cut-off and saturation.
 Advantages:Advantages:
• SpeedSpeed
• good fan – in and fan – outgood fan – in and fan – out
• easy interface with other digital circuitryeasy interface with other digital circuitry

44. Computer Architecture
& Microprocessor
4444
Flip FlopFlip Flop
 Stores a binary digitStores a binary digit
 Stable till a signal switches itStable till a signal switches it
 Types of Types of flip flopTypes of Types of flip flop
 S-R flip flopS-R flip flop
 J-K flip flopJ-K flip flop
 D flip flopD flip flop
 T flip flopT flip flop

45. Computer Architecture
& Microprocessor
4545
RegistersRegisters
 Group of flip-flopsGroup of flip-flops
 Connected in parallelConnected in parallel
 D flip-flop commonly usedD flip-flop commonly used
Shift RegisterShift Register
 Shifts content unchangedShifts content unchanged
 Temporary storageTemporary storage
 Types:Types:
 Serial-in, serial-outSerial-in, serial-out
 Serial-in, parallel-outSerial-in, parallel-out
 Parallel in, serial-outParallel in, serial-out
 Parallel in, parallel outParallel in, parallel out

46. Computer Architecture
& Microprocessor
4646
CountersCounters
 Counts no. of pulsesCounts no. of pulses
 Modulus of CounterModulus of Counter
• Binary CounterBinary Counter
• Decade CounterDecade Counter
• Pre settable CounterPre settable Counter
Binary CounterBinary Counter
J
k
Q
Q
J
k
Q
Q
J
k
Q
Q
J
k
Q
Q
CLK
3 2 1 0

47. Computer Architecture
& Microprocessor
4747
 Types of CountersTypes of Counters
 Up CounterUp Counter
 Down CounterDown Counter
 Up-Down CounterUp-Down Counter
 Controlled CounterControlled Counter
 Ring CounterRing Counter
Synchronous
Asynchronous

48. Computer Architecture
& Microprocessor
4848
Computer LanguagesComputer Languages
 Machine LanguageMachine Language
–– 0 and 10 and 1
 Assembly LanguageAssembly Language
–– mnemonicsmnemonics
–– assemblerassembler
 High Level LanguageHigh Level Language
–– English like languageEnglish like language
–– Interpreters and CompilersInterpreters and Compilers

49. Computer Architecture
& Microprocessor
4949
Execution of Assembly Language programExecution of Assembly Language program
Source Program
Assembler
Object Program
Loader
Floppy Disk
Floppy Disk
 One to One Translation

50. Computer Architecture
& Microprocessor
5050
Execution of High Level LanguageExecution of High Level Language
Source Code
Translator
Object Code 1 Object Code 2 Object Code 3
 One to Many Translation

51. Computer Architecture
& Microprocessor
5151
Compiler & InterpreterCompiler & Interpreter
 Interpreter translates line by lineInterpreter translates line by line
- Slower- Slower
 Compiler translates the entire codeCompiler translates the entire code
- faster- faster