Altera MAX II devices offer hot-socketing &812; also known as hot plug-in or hot swap &812; and power sequencing support. Designers can insert or remove a MAX II board in a system during operation without undesirable effects to the system bus. The hot-socketing feature removes some of the difficulty faced by designers when using components on printed circuit boards (PCBs) that contain a mixture of 3.3-, 2.5-, 1.8-, and 1.5-V devices.

The MAX II device hot-socketing feature provides: support for board or device insertion and removal without system power-down; support for any power-up sequence; and non-intrusive I/O buffers to system buses during hot insertion.
This paper describes I/O characteristics for different MAX II hot-socket cases.