Architecture and CAD for Deep-Submicron FPGAS pp 105-126 | Cite as
Global Routing Architecture
Abstarct
In this chapter we investigate which global routing architectures lead to the best FPGA area-efficiency [2, 3]. We use the term global routing architecture to refer to the distribution of routing tracks across an FPGA; that is, the relative number of tracks contained in each channel of the FPGA. In the next section we describe some of the different types of global routing architectures, and explain why this is an important problem in FPGA design. Section 5.2 describes the experimental flow we use to evaluate different global routing architectures — this flow is based on the CAD tools described in Chapters 3 and 4. In Section 5.3 we investigate directionally-biased global routing architectures, in which the channels in the vertical direction have a different width than those in the horizontal direction. Section 5.4 examines non-uniform global routing architectures, which have wider channels in some regions of the FPGA than in others.
Keywords
Channel Capacity Directional Bias Logic Block Horizontal Channel Benchmark CircuitPreview
Unable to display preview. Download preview PDF.
Notes
- 1.Note that any given channel will always have the same number of tracks along its entire length. We did not consider varying the channel capacity along its length as this makes it very difficult, and likely impractical, to lay out the FPGA.Google Scholar
- 1.Track segments are counted whether or not they are actually used, so this is a true representation of the area that must be devoted to routing in the layout.Google Scholar