how to convert floating numbers in hex to use in assembly?

[smartshashi]

convert floating point to binary assembler

I am working on butterworth IIR filter & I have to implement it in ARM assembly. This filter have some fractional coefficients. Can anybody explain me how to convert this fractional coefficients in hex so that I can use it in assembly without changing the response of filter?

 

[Kral]

convert to negative floating number to hexa

smartshashi,
You can easily convert decimal fractions to hex using a calculator. Supporse you're working with 16 bit numbers.
Step 1: multiply the fraction by 65536 (2^16)
Step 2: Convert to hex. This is easy on a scientific calculator.
The result is a binary fraction with the MSB having a weight of .5, the 2nd MSB having a weight of .25, etc.
.
Example, convert 0.75 to hex
Step 1: 0.75 X 65536 = 49152
Step 2 convert to hex = C000 (.5 + .25)
.
For negative numbers, just take the 2's complement as you would for an integer. This is done by complementing all the bits and adding 1 (Throw away the carry, if any)
.
When you are done, of course, you must divide the result by 65536 to get the proper scaling.
Regards,
Kral

 

[Enlightenment]

convert binary fraction to hexadecimal

Tip: Read about fixed-point math.

https://en.wikipedia.org/wiki/Fixed-point_arithmetic

**broken link removed**

 

[xie.qiang]

convert fixed point to hex

I think you need to konw what algorithm you want, either Fix-Point alogrithm or floating-point alogrithm, for fix-point, the above explaination is sufficient, but for floating-point, you need to convert the hex-reprensentation of your floating numbers, and again you need to designate in your assemble code that your hex nubmer is represent of floating numbers. I do not konw how to do this..