A New Switch Block for Segmented FPGAs

FPGA Architecture: Survey and Challenges

“…Midpoint-to-midpoint connections are made using single disjoint connections. Example switch blocks in this style include the Imran [146] and shifty [130] switch blocks. The Imran switch block uses a Wilton switch block to connect endpoints of wires and single-transistor disjoint connections to connect midpoints.…”

“…The Imran switch block uses a Wilton switch block to connect endpoints of wires and single-transistor disjoint connections to connect midpoints. This switch block has been shown to be more area efficient than disjoint, universal, or Wilton switch blocks [146]. The shifty switch block similarly allows for domain changes on endpoint turns and disjoint connections at midpoints.…”

FPGA switch block layout and evaluation

“…Wilton [12] presented a switch block architecture which is routable in a fewer number of tracks than the subset architecture. The use of this basic architecture to create FPGAs with wires that span multiple logic blocks is described in [10]. This design is extended in [6] to generate rectangular switch blocks, were the number of vertical and horizonal tracks is not necessarily equal.…”

“…In papers such as [11,12,10,6], as well as the VPR tool, layout area is modeled as a linear relationship with the number of switches, which fails to consider the connections between those switches. Our study focusses on the issue of interconnection and placement of configuration and switch resources.…”

“…shields can be added between signal wires to reduce coupling and its associated delay; and 3. more wires that travel more than basic layout tile can be routed through the switch block. This will significantly improve routability and delay [7,3,10]. Figure 7 illustrates the vertical wires in a layout consisting of two switch blocks and a connection block between them.…”