Page 19 - DCAP108_DIGITAL_CIRCUITS_AND_LOGIC_DESIGNS
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Digital Circuits and Logic Design



                   Notes

                                      2AB =?   2
                                            16
                                        Solution:
                                        Step 1: Convert decimal equivalent each hexadecimal digit to 4 binary digits.

                                                                  2   =  2  = 0010
                                                                   16   10     2
                                                                 A   =  10 = 1010 2
                                                                         10
                                                                   16
                                                                  B   =  11 = 1011
                                                                   16    10    2
                                       Step 2: Combine the binary groups.
                                               0010 0010 1011
                                         2AB =
                                            16   2   A    B
                                         Hence, 2AB  = 001010101011
                                                  16            2
                                 Table 1.4 summarizes the relationship among decimal, hexadecimal, binary, and octal number
                                 systems. Note that the maximum value for a single digit of octal (7) is equal to the maximum
                                 value of three digits of binary. The value range of one digit of octal duplicates the value range of
                                 three digits of binary. If we substitute octal digits for binary digits, the substitution is on a one-
                                 to-three basis. Hence, computers that print octal numbers instead binary, while taking memory
                                 dump, save one-third of printing space and time.

                                 Similarly, note that the maximum value of one digit in hexadecimal is equal to the maximum
                                 value of four digits in binary. Hence, the value range of one digit of hexadecimal is equivalent to
                                 the value range of four digits of binary. Therefore, hexadecimal shortcut notation is a one-to-four
                                 reduction in space and time required for memory dump.
                                  Table 1.4: Relationship among Decimal, Hexadecimal, Binary, and Octal Number Systems


                                                   Decimal  Hexadecimal    Binary     Octal
                                                      0          0           0          0
                                                      1          1           1          1
                                                      2          2           10         2
                                                      3          3           11         3
                                                      4          4          100         4
                                                      5          5          111         5
                                                      6          6          110         6
                                                      7          7          111         7
                                                      8          8          1000        10
                                                      9          9          1001        11
                                                      10         A          1010        12
                                                      11         B          1011        13
                                                      12         C          1100        14
                                                      13         D          1101        15
                                                      14         E          1110        16
                                                      15         F          1111        17
                                                      16         10        10000        20






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