Subnormals

Versal ACAP DSP Engine Architecture Manual (AM004)

Document ID
AM004
Release Date
2022-09-11
Revision
1.2.1 English

The IEEE term for denormal is subnormal. The following explains how DSP58 behaves when it detects a subnormal input and when it creates a subnormal output.

  • When the DSP58 detects a subnormal operand, it treats the operand as zero with the sign of the original operand.
  • When the DSP58 creates a subnormal output, it flushes the output to zero and the sign is preserved as a result of the mantissa of the adder. For the multiplier, the sign is the XOR of the signs of both inputs.