Vlsi ieee projects
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The document discusses the importance of ultra low power design techniques for full adders in mobile VLSI systems due to the limitations of battery technology and the need for high-performance, low-power components. It outlines the implementation of a full adder using branch-based and pass transistor logic, achieving a reduction in transistor count and improves overall performance and efficiency. The findings demonstrate that the 8-bit ripple-carry adder constructed with this ultra low power full adder design achieves over 50% reductions in both total and leakage power compared to traditional methods.
Vlsi ieee projects
- 1. Presented by : Silicon Mentor www.siliconmentor.com Applications of Ultra Low Power Technique On FULL Adder
- 2. Outline INRODUCTION SOLUTIONS FULL ADDER USES OF FULL ADDER ULTRA LOW POWER DESIGN OF FULL ADDER DIAGRAM OF ULPFA ADVANTAGES 8-BIT RIPPLE-CARRY ADDER CONCLUSION
- 3. INTRODUCTION • Recently, building low-power VLSI systems has emerged as highly in demand because of the fast growing technologies in mobile communication and computation. • The battery technology doesn’t advance at the same rate as the microelectronics technology. • There is a limited amount of power Available for the mobile systems. • We are faced with more constraints: high speed, high throughput, small silicon area, and at the same time, low-power consumption.
- 4. HOW WE CAN REDUCE THIS? • Building low-power, high-performance adder cells is of great interest. • By suitable power management, particularly as systems spend most of their time in standby mode. • By design low-power (LP) circuits. This choice closely depends on the design style used. • Full adders have been investigated by the academic and industrial research communities. The usual performance evaluations are speed, power consumption, and area.
- 5. FULL ADDER • A Full Adder is a combinational digital circuit that performs basic addition of binary inputs; • Full adder operation provides with Sum (S) and Carry-over (Cout) output;
- 6. USES OF FULL ADDER • Basic building block of on-chip libraries. • Configured according to desired complexity of arithmetic and numeric computations. • In processors and other kinds of computing devices, adders are used in the arithmetic logic unit. • Adders also use in other parts of the processor, where they are used to calculate addresses, table indices, and similar operations.
- 7. ULTRA LOW POWER FULL ADDER • The logic styles used to implement the hybrid adder: BBL-logic(Branch-Based logic):for carry block. PT-Logic(Pass Transistor): for sum block • Implementation of sum block using BBL requires 24 transistors, which is not advantageous.So the sum block has been implemented using pass transistor logic.
- 8. BLOCK DIAGRAM PASS TRANSISTOR : BRANCH BASED LOGIC:
- 9. ADVANTAGES OF ULPFA • implementation of the full-adder with the BBL-PT logic style only 23 transistors are used. • But in CMOS full adder 28-transistor and in CPL full adder 32- transistor are used. • So BBL-PT full adder is more advantageous.
- 10. Ripple Carry Adder(RCA) Using Full Adder As Basic Cell • A standard 8-bit Ripple-Carry Adder(RCA) built as a cascade from eight 1-bit full-adders
- 11. Circuit Description • Each full adder inputs a Cin, which is the Cout of the previous adder. This kind of adder is a Ripple Carry Adder. • Each carry bit "ripples" to the next full adder. • Each stage of the adder has to wait until the previous stage has calculated and propagates its carry output signal.
- 12. CONCLUSION • The power consumption is decrease due to the reduction of transistors. • The total layout area also reduce. • The packing density is increase because of the less number of transistor. • The speed and performance of the cell is also increase. • The 8-bit RCA circuit based on the ULPFA achieves both total and leakage power reductions of more than 50% compared to the 8-bit RCA circuit implemented with a conventional static CMOS full adder.
- 13. Contact Us for M.tech/PhD Research Project Guidance Phone : 08130809758 Email: [email protected] THANK YOU