Scaling - 2023.2 English

Vitis Libraries

Release Date
2023.2 English

Scaling in the FFT window is controlled by the TP_SHIFT parameter which describes how many binary places by which to shift the result to the right, i.e. only power-of-2 scaling values are supported. For integer types, it is suggested that the window coefficient values approach the maximum positive value which can be expressed the type selected, to maximize the number of significant digits. e.g. the provided utility functions scale int16 windows to a maximum value of 2^14 and therefore a TP_SHIFT value of 14 will normalize output values and ensure saturation does not occur.

No scaling is applied at any point when the data type is cfloat. Setting TP_SHIFT to any value other than 0 when TT_DATA is cfloat will result in an error.