Incorrect Handling of “Saturation” in FFT Hardware Accelerator’s Input / Output Formatter and Statistics Block
Revision(s) Affected:
IWR1443 ES1.0, IWR1443 ES2.0, and IWR1443
ES3.0
Description:
- Input formatter block
performs saturation based on signed or unsigned samples. However, the
compute engine module always saturates the input as a 24 bit signed
number.
- Output formatter block
saturates the 16 bits unsigned number as signed number. This causes
magnitude outputs to have a smaller max range.
- Statistics block always
assumes that input is signed when checking for saturation, but the input can
be unsigned in some cases.
Workaround(s):
None, there is no planned update.
The max output range must be 16 bit signed. The statistics block input should be
a signed input.