Microprocessor with alu integrated into load unit

Abstract

A superscalar pipelined microprocessor includes a register set defined by an instruction set architecture of the microprocessor, execution units, and a store unit, coupled to the cache memory and distinct from the other execution units of the microprocessor. The store unit comprises an ALU. The store unit receives an instruction that specifies a source register of the register set and an operation to be performed on a source operand to generate a result. The store unit reads the source operand from the source register. The ALU performs the operation on the source operand to generate the result, rather than forwarding the source operand to any of the other execution units of the microprocessor to perform the operation on the source operand to generate the result. The store unit operatively writes the result to the cache memory.

Description

technical field [0001] The present invention mainly relates to the technical field of microprocessors, in particular to a microprocessor architecture (microarchitecture) of a microprocessor. Background technique [0002] A typical example of an RISC processor is that the processor uses a load / store architecture, that is, the processor includes a load instruction to load an operand from memory to the processor A register of the processor, the processor also includes a store instruction for storing an operand in a register of the processor into memory. In a typical example, the load and store instructions described above are the only instructions that access memory, while other instructions that perform arithmetic / logic operations receive their respective operands from registers and write the results to registers, i.e., non-load Or store instructions are not allowed to specify operands in memory, which allows most non-load or store instructions to be executed in a single freq...

AI Technical Summary

Problems solved by technology

[0004] The advantage of using different load / store units and ALUs is that the architecture is simple and fast. However, the disadvantage is that it takes a lot of time to transfer the results between the various units through the registers. Part of this problem can be solved by transferring The transfer bus is used to transfer a result from one execution unit to another directly without going through registers, but this still has the problem of time consumption, that is, the delay that occurs during the transfer ( delay) situation

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