Apparatus and method for protecting memory in multi-processor system

摘要

Memory mapping in small units using a segment and subsegments is described, and thus it is possible to control a memory access even using a small amount of hardware, and it is possible to reduce costs incurred by hardware. Additionally, it is possible to prevent a memory from being destroyed due to a task error in the multi-processor system.

主权项

1. A memory protection method, comprising:
extracting a segment address and a subsegment address from a memory address of a memory access, when a Central Processing Unit (CPU) attempts the memory access with respect to a memory; comparing the extracted segment address with a segment base address comprised in a segment register, the segment base address being of a segment of the memory; transmitting an exception signal to the CPU when the extracted segment address is different from the segment base address, the exception signal indicating that the memory access is disallowed; determining whether the extracted subsegment address matches any of one or more subsegment addresses comprised in a subsegment register corresponding to the segment base address, the one or more subsegment addresses being of one or more subsegments of the segment; transmitting the exception signal to the CPU when the extracted subsegment address does not match any of the one or more subsegment addresses; determining whether the extracted subsegment address is mapped based on a map bit comprised in the segment register, when the extracted subsegment address matches any one of the one or more subsegment addresses; and transmitting the exception signal to the CPU when the extracted subsegment address is unmapped.