TUSER Fields - 9.1 English - PG109

Fast Fourier Transform LogiCORE IP Product Guide (PG109)
Document ID
PG109
Release Date
2024-11-13
Version
9.1 English

The Data Output channel carries the fields in the following table in its TUSER vector.

Table 1. Data Output Channel TUSER Fields
Field Name Width Padded Description
XK_INDEX log2 (maximum point size) Yes - zero extended Index of output data (unsigned 2's complement). This field is optional, and only included when XK_INDEX is enabled in the IDE.
BLK_EXP 8 Yes - zero extended

Block exponent (unsigned 2's complement): The amount of scaling applied (that is, the number of bits by which the otherwise unscaled output value has been shifted down). A separate BLK_EXP field is included for each FFT channel that the core has.

Available only when block floating-point is used.

For more information on BLK_EXP, see Block Exponent.
OVFLO 1 No

Arithmetic overflow indicator (single bit, active-High): OVFLO is High during result unloading if any value in the data frame overflowed. The OVFLO signal is reset at the beginning of a new frame of data.

A separate OVFLO field is included for each FFT channel that the core has.

This port is optional and only available with scaled arithmetic or single precision floating-point I/O.

For more information on OVFLO, see Overflow.

All fields with padding should be 0 extended to the next 8-bit boundary if they do not already finish on an 8-bit boundary.