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.