What is vailue of scale_sch for Inverse FFT in IP core FFT5.0 in VHDL

[varun_agr]

We are using scaling in FFT5.0 IP Core for 64 transform size,radix 2 burst mode,natural order,scaling(so get same o/p size as i/p size), i/p data 8 bit and expected o/p data also 8 bit. For this we scale for FFT in FFT5.0 IP CORE using trial method and using scale_sch="010101010101" in this case no overflow and for scale_sch="010101010100" it is overflow .But when we give o/p of FFT to I/p of IFFT (as we want to reuse same core) then in every scale_sch value there is no overflow. So what should be vaule of scale_sch for IFFT. Can anybody suggest me?
Before FFT I am using 50 hz sine wave using ADC and after IFFT I am using DAC and I want to remove all noise except 50 Hz component. Can anybody suggest me the process after FFT.

varun