1.3.2 Hot Socketing (GPIO Only)

Hot socketing (also known as hot swapping or hot plug-in) prevents damage to the PolarFire SoC FPGA if, at any time, voltage is detected at I/O while the device is powered OFF. It also helps prevent disruptions that may occur in the rest of the system if the I/O of a device are connected without a valid power supply.

Only GPIOs support hot socketing. In hot socketing, GPIOs are in high-impedance (hi-Z) state.

The GPIO maintains the following high-impedance state until the power supplies are at a valid state.

• VDDAUx is greater than or equal to 1.6V
• VDDIx is greater than or equal to 0.8V
• VDD and VDD25 are both high and the PolarFire SoC FPGA controller has asserted the global I/O ring signal (IO_EN)