Institute of Applied Microelectronics and Computer Engineering

College of Computer Science and Electrical Engineering, University of Rostock Slide 1

Institute MD, University of Rostock

Spezielle Anwendungen des VLSI – Entwurfs

Applied VLSI design

Course and contest

Phase 2

Robert Balla und Henning Puttnies

Institute of Applied Microelectronics and Computer Engineering

College of Computer Science and Electrical Engineering, University of Rostock

• Special multipliers• 1-Operand-Multiplier (generic Value)• CSD-Recoding• Carry-Save-Adders with T≠O(n)• 2 Output Signals

• (4,2)-Compressors with T≠O(n)• Only 1 CPA in the whole Design

Slide 2

Implementation

Institute of Applied Microelectronics and Computer Engineering

College of Computer Science and Electrical Engineering, University of Rostock

Carry Propagate Adder

Slide 3

 

 

 

• Ladner-Fischer-Adder• Parallel-Prefix-Adder with minimum logic

depth• Latency of O(log(n))• Consists of Carry operators

Institute of Applied Microelectronics and Computer Engineering

College of Computer Science and Electrical Engineering, University of Rostock Slide 4

Institute of Applied Microelectronics and Computer Engineering

College of Computer Science and Electrical Engineering, University of Rostock

Meric and Improvements

Phase 1 Phase 2 Increase

Frequency [MHz] 49.405 426,075 760%

# LUTs 7063 1775 -75%

# Registers 704 2523 250%

# Pipeline Stages 1 16

Metric 0.3715 17,1

Slide 5

Further Improvements• Edit width of the coefficients• Use Tree-Structure of Multipliers• Test more CPAs

Institute of Applied Microelectronics and Computer Engineering

College of Computer Science and Electrical Engineering, University of Rostock

Quellen

[1] Systemgerechte Algorithmen, Prof. D. Timmermann, Vorlesungsmitschrift SS 13

[2] Fast Multiplication: Algorithms and Implementation, Gary W. Bewick

1994

[3] Hardware algorithms for arithmetic modules

http://www.aoki.ecei.tohoku.ac.jp/arith/mg/algorithm.html#fsa_cla

Slide 6