Float

Floating Point Info

My calculator WristApps currently use "S16E7" floating point numbers which are accurate to 4 decimal places and have a range of ~3*10^7. 

S16E7 appears to be used mainly in video cards.  It means 1 bit for sign (S), 16 bits for the mantissa, and 7 bits for the exponent (E).

Since S16E7 is not an IEEE standard, there are probably some variations in format.  I'm using a biased exponent (the real exponent is 63 decimal less than as stored) and an unpacked mantissa (the leading 1 in the mantissa is often used for something else since it is assumed to always be a 1, but I'm not doing that to make my programs smaller).

Convert an IEEE-754 32-bit float in hex to an S16E7 float in hex (and back again):

  IEEE-754 HEX                                                                                         S16E7 HEX

       

 

 

Use this page to convert between decimal numbers and IEEE-754 hex:   

Decimal to IEEE-754:  https://babbage.cs.qc.cuny.edu/IEEE-754.old/Decimal.html

IEEE-754 to Decimal:  https://babbage.cs.qc.cuny.edu/IEEE-754.old/32bit.html

And also this new version:  https://babbage.cs.qc.cuny.edu/IEEE-754/

 

 

IEEE-754 Floating Point Math Links

https://steve.hollasch.net/cgindex/coding/ieeefloat.html

 http://iftekhar-ahmed.blogspot.com/2011/09/ieee-754-floating-point-multiplication.html

https://apropos-logic.com/demos/3-2-floating-point-formats/

http://meseec.ce.rit.edu/eecc250-winter99/

Copyright 2001-2019  Raymond J. Allen