Institute of Applied Microelectronics and Computer Engineering College of Computer Science and Electrical Engineering, University of Rostock Spezielle Anwendungen des VLSI-Entwurfs Special applications of VLSI design Prof. Dirk Timmermann, Claas Cornelius, Stephan Kubisch, Frank Sill, and Harald Widiger Course and contest Student: Enrico Daum

Institute of Applied Microelectronics and Computer Engineering College of Computer Science and Electrical Engineering, University of Rostock Spezielle Anwendungen des VLSI-Entwurfs Special applications of VLSI design reminder design: implement Carry Save Adders (chain of full- adders, that generate SUM and CARRY) using a Ripple Carry Adder to add Sum- sequence and Carry- Sequence results (after optimization): max. frequency : 125 MHz delay path : 14 CSA & 16 RPA stages

Institute of Applied Microelectronics and Computer Engineering College of Computer Science and Electrical Engineering, University of Rostock Spezielle Anwendungen des VLSI-Entwurfs Special applications of VLSI design optimization Check out and reduze unused and oversized registers Speed increased : from 123 MHz upto 125 MHz synthesise: first idea Synthesize with Xilinx- ISE frequency & try out different parameters like: min_delay, max_transition etc. result: no observable improvement

Institute of Applied Microelectronics and Computer Engineering College of Computer Science and Electrical Engineering, University of Rostock Spezielle Anwendungen des VLSI-Entwurfs Special applications of VLSI design test maximum frequency in consideration of the slack result: design synthesizeable without violation with 580MHz synthesise: second idea calculation f (frequency) PEP (power energy product) P=scaled powercons.

Institute of Applied Microelectronics and Computer Engineering College of Computer Science and Electrical Engineering, University of Rostock Spezielle Anwendungen des VLSI-Entwurfs Special applications of VLSI design results

Institute of Applied Microelectronics and Computer Engineering College of Computer Science and Electrical Engineering, University of Rostock Spezielle Anwendungen des VLSI-Entwurfs Special applications of VLSI design conclusion & problems unexpected results! (esp. linear ascending PEP upto 500MHz and then nearly straight-lined problems with the non-working optimized parameters like: preferring max_transition or min_delay lack of knowledge of used cell- libraries