Data processor system including data-save controller for protection against loss of volatile memory information during power failure

摘要

A data processing system, having a volatile main memory prepares for power supply failure, at the first instance of power supply potential falling below a predetermined limit, by readying its current task for restart, data-saving by storing the contents of volatile, processor registers in the main memory, and completing any non- postponable tasks. If power deficiency lasts for longer than a predetermined period, the memory is maintained by a battery power source if and only if data-saving has been completed. Restoration of power during the predetermined period causes instant reversal and restart, but after the elapse of the predetermined period, causes reversal and restart if and only if a data save has been completed, otherwise causing reinitialization.