DMC - Spatial Locality

Spatial Locality is the idea that if a memory address is referenced, nearby addresses are likely to be referenced soon

• One-block cache lines don't take advantage of this, therefore:

We make each cache line two blocks
Then, we can group the memory addresses into pairs

• i.e. addresses 0 and 1 become block address 0

In this example, if a program reads from byte address $4$ we'll load all of memory block $2$ ( Both addresses $4$ and $5$ ) into cache line $2$

• A read from address $5$ will also cause memory block $2$ to be loaded into cache line $2$
  
  As a result we must change how the memory address is formatted
  
  It is still the same as the Normal DMC Formatting however,
• A final bit is added to choose a block/cache line
• The valid bit is removed
• And the address used is the block address not the memory address
  The Loading function is similarly changed

Types of Cache Misses

• Compulsory Miss
  • These misses occur when the first access to a block happens
    As there is no valid bit
• Conflict Miss
  • These misses occur when several blocks are mapped to the same cache line