A.1.5. Cache incoherence check

Rating: 5.

When the parameter vmsa.cache_incoherence_check is set, the model warns about any data-side memory read accesses whose result could have been ambiguous because of incoherency in the system. The warning contains the physical address being accessed, and at least two data values that could have been the result.

For example, consider an area of memory that has been copied into the Level 1 cache. If the memory is changed by an external agent, then a read to these addresses could return either the old value from the cache or the new value if that cache line is evicted.

Similar effects can occur in MP systems if newer values are pending in the writebuffer, or in a writeback cache block outside the inner shared domain.

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