PCM for main memory IiSCAs'O7 [ISCA09 Optimization on pCm write [MICRO09 Optimization data comparison write Goal: write only modified bits rather than entire cache line Approach: read-compare-write CPU cache010110000110101 0 0110 01|101110 rea PCM po1o1oaao1o1叫1• Optimization: data comparison write • Goal: write only modified bits rather than entire cache line • Approach: read-compare-write 0 1 0 1 1 0 1 1 0 1 1 0 1 1 1 0 0 1 0 1 1 0 10 10 0 1 1 0 1 10 1 01 0 1 0 1 1 0 1 1 0 1 1 0 1 1 1 0 0 1 0 1 1 0 0 0 0 1 1 0 1 0 1 1 CPU cache PCM PCM for main memory Optimization on PCM write [ISCAS’07] [ISCA’09] [MICRO’09] read