Control register mapping in heterogenous instruction set architecture processor

摘要

A microprocessor supports an instruction set architecture that specifies: processor modes, architectural registers associated with each mode, and a load multiple instruction that instructs the microprocessor to load data from memory into specified ones of the registers. Direct storage holds data associated with a first portion of the registers and is coupled to an execution unit to provide the data thereto. Indirect storage holds data associated with a second portion of the registers and cannot directly provide the data to the execution unit. Which architectural registers are in the first and second portions varies dynamically based upon the current processor mode. If a specified register is currently in the first portion, the microprocessor loads data from memory into the direct storage, whereas if in the second portion, the microprocessor loads data from memory into the direct storage and then stores the data from the direct storage to the indirect storage.