Much of the area of an FPGA is taken up with programmable wiring. The pass transistor is a cheap (in area terms) and efficient (in delay terms) form of programmable wiring, but it does not amplify the signal.
FPGAs dominate the recent history of reconfigurable computing but are fine-grain owing to heritage in hardware circuits. There is an argument for having wider busses as the lowest programmable feature, which amortises the programming overhead to some extent, and yields the CGRA - coarse grain reconfigurable array.
| 28: (C) 2008-18, DJ Greaves, University of Cambridge, Computer Laboratory. |