An architecture of hierarchical interconnect scheme for field programmable
gate arrays (FPGAs). A first layer of routing network lines is used to
provide connections amongst sets of block connectors where block
connectors are used to provide connectability between logical cells and
accessibility to the hierarchical routing network. A second layer of
routing network lines provides connectability between different first
layers of routing network lines. Additional layers of routing network
lines are implemented to provide connectability between different prior
layers of routing network lines. An additional routing layer is added
when the number of cells is increased as the prior cell count in the
array increases while the length of the routing lines and the number of
routing lines also increases. Switching networks are used to provide
connectability among same and different layers of routing network lines,
each switching network composed primarily of program controlled passgates
and, when needed, drivers.