A selective filter-bank TLB system [embedded processor MMU for low power]

We present a selective filter-bank translation lookaside buffer (TLB) system with low power consumption for embedded processors. The proposed TLB is constructed as multiple banks with a small two-bank buffer, called a filter-bank buffer, located above its associated bank. Either a filter-bank buffer or a main bank TLB can be selectively accessed, based on two bits in the filter-bank buffer. Energy savings are achieved by reducing the number of entries accessed at a time, by using filtering and the bank mechanism. The overhead of the proposed TLB turns out to be negligible compared with other hierarchical structures. Simulation results show that the energy×delay product can be reduced by about 88% compared with a fully -associative TLB, 75% with respect to a filter-TLB, and 51% relative to a banked-filter TLB.