sentences:  Most programmers never need to be aware of the fact that the processor core implements a (modified) Harvard architecture, although they benefit from its speed advantages.Only programmers who generate and store instructions into memory need to be aware of issues such as cache coherency, if the store doesn't modify or invalidate a cached copy of the instruction in an instruction cache.Another change preserves the "separate address space" nature of a Harvard machine, but provides special machine operations to access the contents of the instruction memory as data.