Upgradeable data processing system.

摘要

A data processing system includes a first central processing unit (CPU), at least one expansion port into which additional CPUs may be inserted, and a system controller. Interrupt circuitry coupled to said first CPU, said at least one expansion port, and said system controller, is configured to allow the data processing system to operate as a multi-processor system, only one of the first and additional CPUs communicating with the system controller at any one time.