Hot socketing refers to the capability to insert a board into, or remove a board from, a system during operation without causing negative effects to the system or the board. It is also referred to as “hot swapping” or “hot plug-in.”
Devices in the Stratix® series and Cyclone® series FPGAs, and the MAX® series CPLDs, are designed and tested to offer robust support for on-chip hot-socketing and power-sequence protection without needing additional external devices or board manipulation.
A device must meet three criteria to be considered hot-socketable:
- It can be driven before power up without any damage
- It does not drive out before power up
- It does not drive out during power up
To find out more about the advantages of the on-chip hot-socketing support in Altera® devices, refer to the Altera Hot-Socketing & Power-Sequencing Advantages (PDF) white paper that details Altera’s hot-socketing advantages. For detailed characterization data, refer to the Hot-Socketing & Power-Sequencing Feature & Testing for Altera Devices (PDF) white paper.
For detailed characterization data, refer to the white paper detailing hot-socketing features and testing for Stratix, Stratix GX, Stratix II, Stratix II GX, Stratix III, Cyclone and Cyclone II FPGA families, and MAX V, MAX II, MAX 7000AE and MAX 3000A CPLD families.
Protection in PLDs for High-Availability Systems
Hot socketing is a critical requirement for systems that require high availability (constant system uptime), such as network storage servers or carrier-class telecommunication infrastructures, where each second of system downtime translates directly into revenue losses.
Protection in PLDs for Multi-Voltage Systems
In multi-voltage systems for which hot socketing is not required, hot-socketing and power-sequence protection capability for the PLD is still critical. In these systems, regulators are used to provide different voltage levels and can cause the power-up sequence to become unpredictable; devices that require a predetermined power-up sequence may no longer function properly.
The hot-socketing support in PLDs can alleviate problems in multi-voltage system designs because normal PLD functionality will not be influenced by the system power-up sequence. This can be vital for the common application where CPLDs are used to control the power up of other devices in very complex systems.
Table 1 outlines some example systems in different market segments that benefit from hot socketing in Altera devices.