# Floating point binary number to a 7 segment decimal display

I have covered floating point (32 bit) conversion from float to decimal and decimal to float. I am happy with the theory and I have created a conversion tool in Excel VBA which works just fine following the IEEE754 , so I am happy with theory. Also happy with add, sub , mult , div of 32 bit floating point binary numbers. What I cannot understand or find anywhere online is the answer to this simple question. How do computers / calculators do the final conversion from the floating point binary number onto a display. For eaxmple , I have built a BCD to decimal converter using Logisim (combinational logic gates) and I have built a Binary to Decimal converter in Logisim using the Double Dabble algorithm si I can see how these can display on a set of 7 segment displays but how does the number (0 10000001 01 00 11 00 11 00 11 00 11 00 11 0) which is the floating point binary for decimal number 5.2 actually get converted using logic circuits.

• They have a fixed mapping $\{0,\ldots,9\} \to \{0,1\}^7$ that realizes each digit as a subset of the 7 segments. May 19, 2020 at 11:43
• Thank you. Yes I know about the fixed mappings onto the segments. But what do we convert the floating point binary number to in order to map it onto the segments. Do we convert the floating point binary to BCD or normal binary then map to the segments ? There is a bit in the middle here I am missing. May 19, 2020 at 14:50
• We convert it to decimal. Think of it like a programmer. How would you implement it? May 19, 2020 at 14:51
• I can implement it in code. I am trying to build it in logic gates. I can't figure out the logic elements neccessary to show (0 10000001 01 00 11 00 11 00 11 00 11 00 11 0) as 5.2 on the segments. I may just be having a mind fart about this. May 19, 2020 at 14:56
• I can build a floating point multiplier / divider adder and subtractor as the answer remains in the floating point binary , but to convert answers to decimal using logic gates , this is what I am stuck at. May 19, 2020 at 14:58