You can implement many forms of I/O on FPGA's that let you bridge things that otherwise can't communicate for whatever reason. The FPGA can also be used to acce

You can implement many forms of I/O on FPGA's that let you bridge things that otherwise can't communicate for whatever reason. The FPGA can also be used to accelerate I/O vs a software implementation. For example, many network devices offload TCP/IP from the host. Finally, the connecting systems might have the necessary I/O built-in but FPGA accelerates some computational part of it. You see that in compression, TLS or IPsec engines. I don't know what Bitcoin people are doing. The above are common use cases, though.