As seen in the Inverse Sinc Frequency response, the filter gain is >1. To ensure that the filter output does not overflow, the input signal amplitude must be backed-off to account for this gain factor. The inverse sinc block has automatic overflow detection and saturation, and if overflow is detected, it is flagged using the interrupt mechanism to the RFdc driver API, using the XRFDC_DAC_IXR_INVSNC_OF_MASK interrupt. For more details see Interrupt Handling.