Digital Electronics - ASCII Codes

Previous
Quiz
Next

ASCII stands for American Standard Code for Information Interchange. The ASCII code is a popular coding scheme used in digital computing systems to encode characters.

In the ASCII code, a unique integer value is assigned to each character like number, letter, symbol, etc. The standard ASCII code defines a set of 128 characters, where each character can be represented by a unique 7-bit binary code. Therefore, ASCII code can represent total 27 = 128 possible characters.

In digital electronics, the characters in ASCII code are generally represented in decimal or hexadecimal notation. Overall, the ASCII code is a standard encoding scheme for representing characters in digital computers and communication systems.

Properties of ASCII Code

The following are some key characteristics of ASCII code −

  • ASCII code assigns a unique numeric value to each character.
  • ASCII code provides a way of representing letters, numbers, symbols, and control characters.
  • ASCII code is compatible with a wide range of programming languages and digital devices.
  • ASCII code supports various control characters for basic text formatting and device control.
  • ASCII code has decimal and hexadecimal representation. Hence, it is human-readable.
  • ASCII code assigns numeric values to characters in a sequential order, making it an efficient encoding standard in terms of sorting and searching.
  • ASCII code is highly space efficient and simple.

Types of ASCII Code

ASCII (American Standard Code for Information Interchange) code is basically a 7-bit character encoding standard used in digital electronics. But it is evolved with the advancement in computing technologies.

The following are two main types of ASCII codes −

  • Standard ASCII Code
  • Extended ASCII Code

Let's discuss the Standard ASCII Codes first.

Standard ASCII Code

It is a 7-bit character encoding standard having a range from 0 to 127 i.e., total 128 possible characters. It assigns a 7-bit unique binary code to each character including numbers, letters, symbols, and control characters.

The following table highlights the name, symbol and ASCII code in decimal and binary form for the range from 0 to 127.

Name Symbol Decimal 7-Bit Binary
Null char NUL 0 00000000
Start of Heading SOH 1 00000001
Start of Text STX 2 00000010
End of Text ETX 3 00000011
End of Transmission EOT 4 00000100
Enquiry ENQ 5 00000101
Acknowledgment ACK 6 00000110
Bell BEL 7 00000111
Back Space BS 8 00001000
Horizontal Tab HT 9 00001001
Line Feed LF 10 00001010
Vertical Tab VT 11 00001011
Form Feed FF 12 00001100
Carriage Return CR 13 00001101
Shift Out / X-On SO 14 00001110
Shift In / X-Off SI 15 00001111
Data Line Escape DLE 16 00010000
Device Control 1 (oft. XON) DC1 17 00010001
Device Control 2 DC2 18 00010010
Device Control 3 (oft. XOFF) DC3 19 00010011
Device Control 4 DC4 20 00010100
Negative Acknowledgement NAK 21 00010101
Synchronous Idle SYN 22 00010110
End of Transmit Block ETB 23 00010111
Cancel CAN 24 00011000
End of Medium EM 25 00011001
Substitute SUB 26 00011010
Escape ESC 27 00011011
File Separator FS 28 00011100
Group Separator GS 29 00011101
Record Separator RS 30 00011110
Unit Separator US 31 00011111
Space 32 00100000
Exclamation mark ! 33 00100001
Double quotes " 34 00100010
Hash # 35 00100011
Dollar $ 36 00100100
Percentage % 37 00100101
Ampersand & 38 00100110
Single quote ' 39 00100111
Open parenthesis ( 40 00101000
Close parenthesis ) 41 00101001
Asterisk * 42 00101010
Plus + 43 00101011
Comma , 44 00101100
Hyphen - 45 00101101
Period, dot or full stop . 46 00101110
Slash or divide / 47 00101111
Zero 0 48 00110000
One 1 49 00110001
Two 2 50 00110010
Three 3 51 00110011
Four 4 52 00110100
Five 5 53 00110101
Six 6 54 00110110
Seven 7 55 00110111
Eight 8 56 00111000
Nine 9 57 00111001
Colon : 58 00111010
Semicolon ; 59 00111011
Less than < 60 00111100
Equals = 61 00111101
Greater than > 62 00111110
Question mark ? 63 00111111
At symbol @ 64 01000000
Uppercase A A 65 01000001
Uppercase B B 66 01000010
Uppercase C C 67 01000011
Uppercase D D 68 01000100
Uppercase E E 69 01000101
Uppercase F F 70 01000110
Uppercase G G 71 01000111
Uppercase H H 72 01001000
Uppercase I I 73 01001001
Uppercase J J 74 01001010
Uppercase K K 75 01001011
Uppercase L L 76 01001100
Uppercase M M 77 01001101
Uppercase N N 78 01001110
Uppercase O O 79 01001111
Uppercase P P 80 01010000
Uppercase Q Q 81 01010001
Uppercase R R 82 01010010
Uppercase S S 83 01010011
Uppercase T T 84 01010100
Uppercase U U 85 01010101
Uppercase V V 86 01010110
Uppercase W W 87 01010111
Uppercase X X 88 01011000
Uppercase Y Y 89 01011001
Uppercase Z Z 90 01011010
Opening bracket [ 91 01011011
Backslash \ 92 01011100
Closing bracket ] 93 01011101
Caret - circumflex ^ 94 01011110
Underscore _ 95 01011111
Grave accent ` 96 01100000
Lowercase a a 97 01100001
Lowercase b b 98 01100010
Lowercase c c 99 01100011
Lowercase d d 100 01100100
Lowercase e e 101 01100101
Lowercase f f 102 01100110
Lowercase g g 103 01100111
Lowercase h h 104 01101000
Lowercase i i 105 01101001
Lowercase j j 106 01101010
Lowercase k k 107 01101011
Lowercase l l 108 01101100
Lowercase m m 109 01101101
Lowercase n n 110 01101110
Lowercase o o 111 01101111
Lowercase p p 112 01110000
Lowercase q q 113 01110001
Lowercase r r 114 01110010
Lowercase s s 115 01110011
Lowercase t t 116 01110100
Lowercase u u 117 01110101
Lowercase v v 118 01110110
Lowercase w w 119 01110111
Lowercase x x 120 01111000
Lowercase y y 121 01111001
Lowercase z z 122 01111010
Opening brace { 123 01111011
Vertical bar | 124 01111100
Closing brace } 125 01111101
Equivalency sign (tilde) ~ 126 01111110
Delete 127 01111111

Extended ASCII Code

It is an 8-bit character encoding standard having a range from 0 to 255 i.e., total 256 possible characters. The extended ASCII code adds extra 128 characters to the standard ASCII code.

The following table shows the name, symbol and ASCII code in decimal and binary form for the range from 128 to 255.

Name Symbol DEC BIN
Euro sign 128 10000000
129 10000001
Single low-9 quotation mark 130 10000010
Latin small letter f with hook 131 10000011
Double low-9 quotation mark 132 10000100
Horizontal ellipsis 133 10000101
Dagger 134 10000110
Double dagger 135 10000111
Modifier letter circumflex accent 136 10001000
Per mille sign 137 10001001
Latin capital letter S with caron 138 10001010
Single left-pointing angle quotation 139 10001011
Latin capital ligature OE 140 10001100
141 10001101
Latin capital letter Z with caron 142 10001110
143 10001111
144 10010000
Left single quotation mark 145 10010001
Right single quotation mark 146 10010010
Left double quotation mark 147 10010011
Right double quotation mark 148 10010100
Bullet 149 10010101
En dash 150 10010110
Em dash 151 10010111
Small tilde 152 10011000
Trade mark sign 153 10011001
Latin small letter S with caron 154 10011010
Single right-pointing angle quotation mark 155 10011011
Latin small ligature oe 156 10011100
157 10011101
Latin small letter z with caron 158 10011110
Latin capital letter Y with diaeresis 159 10011111
Non-breaking space 160 10100000
Inverted exclamation mark 161 10100001
Cent sign 162 10100010
Pound sign 163 10100011
Currency sign 164 10100100
Yen sign 165 10100101
Pipe, Broken vertical bar 166 10100110
Section sign 167 10100111
Spacing diaeresis - umlaut 168 10101000
Copyright sign 169 10101001
Feminine ordinal indicator 170 10101010
Left double angle quotes 171 10101011
Not sign 172 10101100
Soft hyphen 173 10101101
Registered trade mark sign 174 10101110
Spacing macron - overline 175 10101111
Degree sign 176 10110000
Plus-or-minus sign 177 10110001
Superscript two - squared 178 10110010
Superscript three - cubed 179 10110011
Acute accent - spacing acute 180 10110100
Micro sign 181 10110101
Pilcrow sign - paragraph sign 182 10110110
Middle dot - Georgian comma 183 10110111
Spacing cedilla 184 10111000
Superscript one 185 10111001
Masculine ordinal indicator 186 10111010
Right double angle quotes 187 10111011
Fraction one quarter 188 10111100
Fraction one half 189 10111101
Fraction three quarters 190 10111110
Inverted question mark 191 10111111
Latin capital letter A with grave 192 11000000
Latin capital letter A with acute 193 11000001
Latin capital letter A with circumflex 194 11000010
Latin capital letter A with tilde 195 11000011
Latin capital letter A with diaeresis 196 11000100
Latin capital letter A with ring above 197 11000101
Latin capital letter AE 198 11000110
Latin capital letter C with cedilla 199 11000111
Latin capital letter E with grave 200 11001000
Latin capital letter E with acute 201 11001001
Latin capital letter E with circumflex 202 11001010
Latin capital letter E with diaeresis 203 11001011
Latin capital letter I with grave 204 11001100
Latin capital letter I with acute 205 11001101
Latin capital letter I with circumflex 206 11001110
Latin capital letter I with diaeresis 207 11001111
Latin capital letter ETH 208 11010000
Latin capital letter N with tilde 209 11010001
Latin capital letter O with grave 210 11010010
Latin capital letter O with acute 211 11010011
Latin capital letter O with circumflex 212 11010100
Latin capital letter O with tilde 213 11010101
Latin capital letter O with diaeresis 214 11010110
Multiplication sign 215 11010111
Latin capital letter O with slash 216 11011000
Latin capital letter U with grave 217 11011001
Latin capital letter U with acute 218 11011010
Latin capital letter U with circumflex 219 11011011
Latin capital letter U with diaeresis 220 11011100
Latin capital letter Y with acute 221 11011101
Latin capital letter THORN 222 11011110
Latin small letter sharp s - ess-zed 223 11011111
Latin small letter a with grave 224 11100000
Latin small letter a with acute 225 11100001
Latin small letter a with circumflex 226 11100010
Latin small letter a with tilde 227 11100011
Latin small letter a with diaeresis 228 11100100
Latin small letter a with ring above 229 11100101
Latin small letter ae 230 11100110
Latin small letter c with cedilla 231 11100111
Latin small letter e with grave 232 11101000
Latin small letter e with acute 233 11101001
Latin small letter e with circumflex 234 11101010
Latin small letter e with diaeresis 235 11101011
Latin small letter i with grave 236 11101100
Latin small letter i with acute 237 11101101
Latin small letter i with circumflex 238 11101110
Latin small letter i with diaeresis 239 11101111
Latin small letter eth 240 11110000
Latin small letter n with tilde 241 11110001
Latin small letter o with grave 242 11110010
Latin small letter o with acute 243 11110011
Latin small letter o with circumflex 244 11110100
Latin small letter o with tilde 245 11110101
Latin small letter o with diaeresis 246 11110110
Division sign 247 11110111
Latin small letter o with slash 248 11111000
Latin small letter u with grave 249 11111001
Latin small letter u with acute 250 11111010
Latin small letter u with circumflex 251 11111011
Latin small letter u with diaeresis 252 11111100
Latin small letter y with acute 253 11111101
Latin small letter thorn 254 11111110
Latin small letter y with diaeresis 255 11111111

Advantages of ASCII Code

The following are the key benefits of the ASCII (American Standard Code for Information Interchange) code −

  • The ASCII code provides a simple and straightforward encoding scheme to represent letters, numbers, and symbols.
  • ASCII code is compatible with a wide range of programming languages and computing devices.
  • ASCII code provides a compact character representation, where each character can be represented using 7-bits or 8-bits. Hence, it is a space efficient encoding standard.
  • ASCII code is a universally adopted encoding standard in the field of digital electronics.
  • ASCII code has easy and simple implementation in hardware and software.

Limitations of ASCII Code

ASCII code has several advantages as described above, but it also has some limitations which are given below −

  • The standard ASCII code has a limited set of 128 characters. This makes it unsuitable for representing characters of languages other than English.
  • The ASCII code can be extended to 8-bits but it is not standardized beyond 7-bits.
  • ASCII code is not suitable to use in systems that require a broad range of characters.

Applications of ASCII Code

ASCII code is a standard character encoding scheme used in wide range of applications in the field of digital electronics.

Some major applications of ASCII code are listed below −

  • ASCII code is used in digital systems for textual communication.
  • ASCII code is used in computer programming to represent alphanumeric data like letters, numbers, symbols, etc.
  • ASCII code is also used in various communication protocols utilized for data transmission among devices.
  • In the field web technology, ASCII code is used to represent different characters and symbols in a webpage.
  • ASCII code is also used in database systems to represent text data.

Conclusion

In conclusion, ASCII (American Standard Code for Information Interchange) is a character encoding scheme widely used in digital systems. It is a 7-bit standard code used to represent a total of 128 characters including numbers, letters, symbols, and control characters.

Print Page
Previous
Next
Advertisements