How many bit widths does a bipolar data use in FINN hardware implementation?

[MFJI]

Hello all, in FINN implementation, there is a data format called bipolar (-1 or 1). Does anyone know how many hardware bit widths a bipolar data use in FINN hardware implementation? Is it 1 bit or 2 bits? Thank you in advance.

[auphelia]

Hi @MFJI,

In FINN we're working with 1-bit bipolar data. That means 0 represents -1 and 1 represents +1. It is more detailed described in the FINN paper and from the tfc_end2end_example Jupyter notebook: Our example network is a quantized network with 1-bit bipolar (-1, +1 values) precision, and we want FINN to implement them as XNOR-popcount operations as described in the original FINN paper.