Bias block not working properly with fixed point data type

Even though in the documentation of the bias block it supports fixed point types, it doesn't behave correctly when given a fixed point input.

I gave a u-1 bias block an input with data type fixdt(0, 12, 0) with value of 2220 and the output was 2220 instead of 2219.

Answer 1

[Fangjun Jiang]

fixdt(0, 12, 0) means "unsigned". The Bias block does the "Y=U+Bias" operation. The value of -1 can't be represented. If you try "Y=U+1", the result is correct.

If you choose fixdt(1,12,0), which means "signed", then "Y=U+1" or "Y=U-1" both show correct result.

[ALi Falahati]

So the issue was with the unsigned data type. Thanks