High Throughput Square Root

Avoiding Overflow in sqrt(x)

If you leave Auto Adapt enabled for this node, overflow still can occur in the sqrt(x) output if all of the following conditions are true:

• The Rounding pull-down menu in the Item tab specifies Round Half Up or Round Half to Even.
• The integer word length of x is an even number.
• The following relationship is true:
  ${\mathrm{fwl}}_{\mathrm{sqrt}}<\lfloor {\log }_2(2^{\frac{{\mathrm{iwl}}_x}{2}}-\sqrt{2^{{\mathrm{iwl}}_x}-2^{{-fwl}_x}})\rfloor$${\mathrm{fwl}}_{\mathrm{sqrt}}<\lfloor {\log }_2(2^{\frac{{\mathrm{iwl}}_x}{2}}-\sqrt{2^{{\mathrm{iwl}}_x}-2^{{-fwl}_x}})\rfloor$
  where fwl refers to the fractional word length of an input and iwl refers to the integer word length of an input.

Complete the following steps to avoid overflow:

1. Select this node on the diagram.
2. Disable Auto Adapt for the Precision option on the Item tab.
3. Configure the Precision, Overflow, and Rounding for the node.

After you complete these steps, High Throughput Square Root no longer adjusts the fixed-point configuration of sqrt(x) automatically. If you change the fixed-point configuration of the x input and still want to avoid overflow, re-enable Auto Adapt. Then, complete the same steps to specify an exact integer word length and ensure that no overflow occurs.