Floating point allocation of bits........

[flukey2005]

I apologise if this is in the wrong forum.
Ok guys,

Right

i have converted 2659 into floating point format which is:

Sign ¦ Exponent ¦ Mantissa
0 ¦ 1100 ¦ 0.101001100011


0.5 =1
0.25 =0
0.125 =1
0.0625 =0
0.03125 =0
0.015625 =1
0.0078125 =1
0.00390625 =0
0.001953125 =0
0.000976563 =0
0.000488281 =1
0.000244141 =1

so all that added up works out to and then multipled by 2^12 works out to be 2659 which is all dandy.

However, for the question we're using a 16 bit processor.

12bits mantissa, 4bits exponent and 1bit for sign = 17bits which is useless for a 16 bit processor.

Can i have 11 bits for the mantissa instead so i can allocate it for a 16 bit processor?
But if i allocate 11 bits for the mantissa wouldn't this make the calculation wrong?

Cheers