Clock gating based energy efficient ALU design and implementation on FPGA

In this paper, latch free clock gating techniques is applied in ALU to reduce clock power and dynamic power consumption of ALU. Clock power is 50%, 41.46%, 51.30%, 55.15% and 55.78% of total dynamic power when device operating frequency is 100MHz, 1GHz, 10GHz, 100GHz and 1 THz. After implementation of clock gating techniques in ALU, Clock power reduces to 17.85%, 23.39%, 26.49% and 27.19% of total dynamic power, when device operating frequency is 1GHz, 10GHz, 100GHz and 1 THz. On 1 THz operating frequency, when we use clock gating, there are 72.77% reduction in clock power, 38.88% reduction in IOs power and 44% reduction in dynamic power in compare to power consumption without using clock gating techniques. Target device is 90-nm Spartan-3. There is 14.57% reduction in junction temperature on 10GHz operating frequency in compare to temperature without using clock gating techniques. Clock gating saves power but increases over all area. There is 32.35%, 37.84%, 43.31% and 44% reduction in dynamic current when we use clock gate on 1GHz, 10GHz, 100GHz and 1THz operating frequency respectively.