Title :
Interconnect driver design for long wires in field-programmable gate arrays
Author :
Lee, Edmund ; Lemieux, Guy ; Mirabbasi, Shahriar
Author_Institution :
British Columbia Univ., Vancouver, BC
Abstract :
Each new semiconductor technology node brings smaller transistors and wires. Although this makes transistors faster, wires get slower. As FPGA device designers strive to obtain the lowest possible circuit delays from a given technology node, they must take an increasingly interconnect-focused viewpoint in the design process. In particular, for long interconnect wires, signals now require rebuffering somewhere in the middle of the wire. This paper presents a framework for designing and evaluating long, buffered interconnect wires in FPGAs with near-optimal delay performance. Given a target physical wire length, width and spacing, the method determines the number, size, and position of buffers required to obtain the fastest signal velocity for programmable interconnect. A metric introduced during the design is the "path delay profile", or the arrival time of a signal at different points of a long wire. This method is used to design buffering strategies for interconnect based on 0.5mm, 2mm, and 3mm wire lengths in 180nm technology. These interconnect designs are coded into VPR along with an improved timing analyzer which accurately determines the "path delay profile" arrival times. Using VPR, average critical-path delay is reduced by 19% for 0.5mm wires and by up to 46% for 3mm wires over previous designs given in Lemieux et al. (2004)
Keywords :
circuit CAD; field programmable gate arrays; integrated circuit interconnections; integrated circuit metallisation; 0.5 mm; 180 nm; 2 mm; 3 mm; buffered interconnect wires; buffering strategy; fastest signal velocity; field-programmable gate arrays; interconnect driver design; long interconnect wires; path delay profile; programmable interconnect; timing analyzer; wire length; wire spacing; wire width; Application specific integrated circuits; Delay effects; Delay estimation; Driver circuits; Field programmable gate arrays; Integrated circuit interconnections; Process design; Repeaters; Signal design; Wires;
Conference_Titel :
Field Programmable Technology, 2006. FPT 2006. IEEE International Conference on
Conference_Location :
Bangkok
Print_ISBN :
0-7803-9729-0
Electronic_ISBN :
0-7803-9729-0
DOI :
10.1109/FPT.2006.270299