Hot socketing and power-sequence-protection are important for high-availability systems and multi-voltage systems. “Hot socketing” refers to the ability to insert a board into or remove a board from a system during system operation without causing undesirable effects to the host system or the cards themselves. This feature also allows the PLDs to resume normal operation regardless of the power sequence.

Altera has a robust design and full support for hot socketing and power sequencing in its advanced FPGA and CPLD devices. This white paper defines the hot socketing feature for FPGA and CPLD devices, discusses their implementations in silicon, and provides characterization work that demonstrates that Altera devices are hot socketable.