Research and Design of Branch Process Unit in "Longtium R" Microprocessor

“Longtium R” is a 32-bit high performance microprocessor developed by Northwestern Polytechnical University.Branch process unit (BPU) of the processor can remarkably reduce the latency caused by control hazard.Through analyzing some algorithms of branch direction predict and some strategies of branch target address predict, under the overall constraints of BPU, appropriately allocating the hardware cost, this paper proposes a new structure of branch process unit, based on a combined branch predictor and improved branch target buffer (BTB) .Comparing to the traditional BPU which is comprised of gshare branch predictor, this one increases prediction accuracy by 1%~2%, with characteristics of small area and low power consumption.