This paper presents a leakage-efficient instruction TLB (Translation Lookaside Buffer) design for embedded processors. The key observation is that when programs enter a physical page, the following instructions tend to be fetched from the same page for a rather long time. Thus, by employing a small storage component which holds the recent address-translation information, the TLB access frequency can be drastically decreased, and the instruction TLB can be turned into the low-leakage mode with the dual voltage supply technique. Based on such a design philosophy, three leakage control policies are proposed to maximize the leakage reduction efficiency. Evaluation results with eight MiBench programs show that the proposed design can reduce the leakage power of the instruction TLB by 50% on average, with only 0.01% performance degradation.

This paper presents a leakage efficient data TLB (Translation Look-aside Buffer) design for embedded processors. Due to the data locality in programs, data TLB references tend to hit only a small number of pages during short execution intervals. After dividing the overall execution time into smaller time slices, a leakage reduction mechanism is proposed to detect TLB entries which actually serve for virtual-to-physical address translations within each time slice. Thus, with the integration of the dual voltage supply technique, those TLB entries which are not used for address translations can be put into low leakage mode (with lower voltage supply) to save power. Evaluation results with eight MiBench programs show that the proposed design can reduce the leakage power of a data TLB by 37% on average, with performance degradation less than 0.01%.