Command stacking apparatus for use in a memory controller

Abstract

In a stack for use in a data processing system memory controller, information which includes data, instructions and/or commands generated by a requesting unit requesting access to memory are accepted and temporarily stored in the stack if such memory is unavailable. The newest information from any requesting unit that must be temporarily stored is stored in the lowest unoccupied level of the stack. Associated with each stack level is a busy flip-flop which is set when the information is stored in its associated stack level. The busy flip-flop is reset when the information is given access to the memory. The level busy flip-flops are monitored to detect when the stack is full thus indicating that further requests be inhibited. By monitoring the number of levels in the stack that are filled at various times, a measure of throughput can be achieved in order to determine whether the stack should be enlarged or made smaller.

Dependencies are inferred from the claim text.