Traditional test generation methodologies for peripheral cores are performed by a skilled test engineer, leading to long generation times. In this paper a test generation methodology based on an evolutionary tool which exploits high level metrics is presented. To strengthen the correlation between high-level coverage and the gate-level fault coverage, in the case of peripheral cores, the FSMs embedded in the system are identified and then dynamically extracted via simulation, while transition coverage is used as a measure of how much the system is exercised. The results obtained by the evolutionary tool outperform those obtained by a skilled engineer on the same benchmark.