Hardware retry trap for millicoded processor

摘要

Retry trap in the processor system detects the occurrence of a hardware retry during a millicode routine. In operation, millicode resets the retry trap to "O" at the start of a millicode sequence that is sensitive to a retry operation being at some stage of the millicode sequence. The millicode routine tests the retry latch state at one or more points in the sequence to determine if a retry has occurred since the start of the sequence, which is sensitive to a retry operation. The action taken in response to a determination that a retry operation has occurred depends upon the type of potential damage to the system state as a result of the occurrence of the retry operation during the millicode sequence.