Here you can ask questions and find or give answers to organizational, academic and other questions about studying computer science.

1.1k questions

1.2k answers

1.6k comments

546 users

Given the ReSy-Float number (exam WS17)

with base=4, 3 exponent bits and 2 mantissa bits (not counting hidden bit?), how can we convert it into a decimal value?

I tried the following approach, but it yields incorrect results:

edit: added original screenshot of exam

This is the Resy-float format where we do not have any hidden bit.

ß = 4^{3}-1 div 2 = 31

Exponent E = 2.4^{2} + 1.4^{1} + 3.4^{0} - 31 = 8

Mantissa M = (2.4^{1} + 3.4^{0}).4^{1-2} = 11.4^{-1}

The represented number x is +M.B^{E} = (11.4^{-1}).4^{8} = +11.4^{7}= 180224

You use 2^{3-1} -1 for the offset \beta. Since it's base 4 there should be 4^{...}.

Also note that \beta = (B^{e}-1) div 2 = (4^{3}-1) div 2 = 31