When an Over-Amplitude occurs the on-chip DSA is automatically set. During this
time the input buffer remains active and the attenuated data is sent to the digital
circuitry, and the 'sticky'
over_voltage output signal
is asserted and remains asserted until you clear it.
To clear the
over_voltage signal assert the
clear_ov signal, which is high active input, and,
when asserted, returns the DSA setting to the previously programmed user value.
The previous figure shows the amplitude over-voltage being set in the presence
of a large signal. The output signal
asserted, and remains set (sticky) until you clear it, while the signal into the
RF-ADC is attenuated automatically (Auto). It also
shows what happens if you clear the event while the large signal persists - it causes
over_voltage signal to reassert and the attenuation
continues to be set automatically. To avoid the
over_voltage signal reassertion while a large signal persists, you should
set the DSA to a high value before asserting
signal, or make sure the input large signal has been attenuated by external devices.
For the attenuation and input voltage specifications see the Zynq UltraScale+ RFSoC Data Sheet: DC and AC Switching Characteristics (DS926).