1 - 111 0001 1001 - 1111 1100 1110 0000 0000 0000 0000 0000 0000 0000 0000 0001 0110 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
1 - 111 0001 1001 - 1111 1100 1110 0000 0000 0000 0000 0000 0000 0000 0000 0001 0110: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
1 - 111 0001 1001 - 1111 1100 1110 0000 0000 0000 0000 0000 0000 0000 0000 0001 0110, a 64 bit double precision IEEE 754 binary floating point representation standard to decimal?
1. Identify the elements that make up the binary representation of the number:
The first bit (the leftmost) indicates the sign,
1 = negative, 0 = positive.
1
The next 11 bits contain the exponent:
111 0001 1001
The last 52 bits contain the mantissa:
1111 1100 1110 0000 0000 0000 0000 0000 0000 0000 0000 0001 0110
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
111 0001 1001(2) =
1 × 210 + 1 × 29 + 1 × 28 + 0 × 27 + 0 × 26 + 0 × 25 + 1 × 24 + 1 × 23 + 0 × 22 + 0 × 21 + 1 × 20 =
1,024 + 512 + 256 + 0 + 0 + 0 + 16 + 8 + 0 + 0 + 1 =
1,024 + 512 + 256 + 16 + 8 + 1 =
1,817(10)
3. Adjust the exponent.
Subtract the excess bits: 2(11 - 1) - 1 = 1023,
that is due to the 11 bit excess/bias notation.
The exponent, adjusted = 1,817 - 1023 = 794
4. Convert the mantissa from binary (from base 2) to decimal (in base 10).
The mantissa represents the fractional part of the number (what comes after the whole part of the number, separated from it by a comma).
1111 1100 1110 0000 0000 0000 0000 0000 0000 0000 0000 0001 0110(2) =
1 × 2-1 + 1 × 2-2 + 1 × 2-3 + 1 × 2-4 + 1 × 2-5 + 1 × 2-6 + 0 × 2-7 + 0 × 2-8 + 1 × 2-9 + 1 × 2-10 + 1 × 2-11 + 0 × 2-12 + 0 × 2-13 + 0 × 2-14 + 0 × 2-15 + 0 × 2-16 + 0 × 2-17 + 0 × 2-18 + 0 × 2-19 + 0 × 2-20 + 0 × 2-21 + 0 × 2-22 + 0 × 2-23 + 0 × 2-24 + 0 × 2-25 + 0 × 2-26 + 0 × 2-27 + 0 × 2-28 + 0 × 2-29 + 0 × 2-30 + 0 × 2-31 + 0 × 2-32 + 0 × 2-33 + 0 × 2-34 + 0 × 2-35 + 0 × 2-36 + 0 × 2-37 + 0 × 2-38 + 0 × 2-39 + 0 × 2-40 + 0 × 2-41 + 0 × 2-42 + 0 × 2-43 + 0 × 2-44 + 0 × 2-45 + 0 × 2-46 + 0 × 2-47 + 1 × 2-48 + 0 × 2-49 + 1 × 2-50 + 1 × 2-51 + 0 × 2-52 =
0.5 + 0.25 + 0.125 + 0.062 5 + 0.031 25 + 0.015 625 + 0 + 0 + 0.001 953 125 + 0.000 976 562 5 + 0.000 488 281 25 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 000 000 000 003 552 713 678 800 500 929 355 621 337 890 625 + 0 + 0.000 000 000 000 000 888 178 419 700 125 232 338 905 334 472 656 25 + 0.000 000 000 000 000 444 089 209 850 062 616 169 452 667 236 328 125 + 0 =
0.5 + 0.25 + 0.125 + 0.062 5 + 0.031 25 + 0.015 625 + 0.001 953 125 + 0.000 976 562 5 + 0.000 488 281 25 + 0.000 000 000 000 003 552 713 678 800 500 929 355 621 337 890 625 + 0.000 000 000 000 000 888 178 419 700 125 232 338 905 334 472 656 25 + 0.000 000 000 000 000 444 089 209 850 062 616 169 452 667 236 328 125 =
0.987 792 968 750 004 884 981 308 350 688 777 863 979 339 599 609 375(10)
5. Put all the numbers into expression to calculate the double precision floating point decimal value:
(-1)Sign × (1 + Mantissa) × 2(Adjusted exponent) =
(-1)1 × (1 + 0.987 792 968 750 004 884 981 308 350 688 777 863 979 339 599 609 375) × 2794 =
-1.987 792 968 750 004 884 981 308 350 688 777 863 979 339 599 609 375 × 2794 = ...
= -207 103 628 206 283 214 260 413 018 692 880 994 223 699 234 034 002 176 782 945 354 726 783 031 282 789 910 087 895 383 701 362 091 427 201 057 601 388 673 071 860 440 856 054 090 598 504 938 072 566 754 848 399 141 204 314 831 760 093 139 210 493 784 896 908 821 934 230 307 544 267 173 459 169 502 893 934 962 016 256
1 - 111 0001 1001 - 1111 1100 1110 0000 0000 0000 0000 0000 0000 0000 0000 0001 0110, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = -207 103 628 206 283 214 260 413 018 692 880 994 223 699 234 034 002 176 782 945 354 726 783 031 282 789 910 087 895 383 701 362 091 427 201 057 601 388 673 071 860 440 856 054 090 598 504 938 072 566 754 848 399 141 204 314 831 760 093 139 210 493 784 896 908 821 934 230 307 544 267 173 459 169 502 893 934 962 016 256(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.