11.5. Hot-Socketing Implementation
The hot-socketing feature tri-state the output buffer during power up and power down of the power supplies. When these power supplies are below the threshold voltage, the hot-socketing circuitry generates an internal HOTSCKT signal.
Hot-socketing circuitry prevents excess I/O leakage during power up. When the voltage ramps up very slowly, I/O leakage is still relatively low, even after the release of the POR signal and configuration is complete.
The POR circuitry monitors the voltage level of the power supplies and keeps the I/O pins tri-stated until the device is in user mode. The weak pull-up resistor (R) in the Arria® V input/output element (IOE) is enabled during configuration download to keep the I/O pins from floating.
The 3.3-V tolerance control circuit allows the I/O pins to be driven by 3.3 V before the power supplies are powered and prevents the I/O pins from driving out before the device enters user mode.
Did you find the information on this page useful?