I16 U16 FPGA

[david uang]

Hi all,

 I confused myself with the I16 and U16 data representation. Here is how I think about those representations.
 Both the representation use the binary-complement storage. When I convert and I16 to U16, no change is made to the actual storage. Therefore, it does not matter what type I use in the vi as long as I use either U16 or I16.
 Now take an example.  Say, I had a -300 stored in I16 in the host VI. I converted it to U16, and then passed the converted value into a Control of a FPGA vi with type I16. Then I passed the value to the DAC output. I could still get a analog output corresponding to -300/8192. (ignore those upconversion...)
  Am I right? I would really appreciate your comments.

David

SORRY.  I just realized I did not post it in the appropriate board but I can not delete it.

Message Edited by david uang on 04-11-2007 09:22 PM

[AdnanZ]

Hi David,

I hope you are doing well today! I don't understand your question over here. There is a difference between the signed 16 (I16) and unsigned 16 (U16) integers. Only the signed integer uses two’s-complement for representation. So, when you convert an integer from I16 to U16, a change IS made. In the example cited above, -300 becomes 65236. Please do let me know if I have not replied to your question well.