Licenses are required for each FPGA, and each license is tied to a particular FPGA's unique identifier. Licenses may also have a maximum version number and release date that they support. Additional or replacement licenses can be purchased by contacting or Achronix.

The CAIMAN-ASR server can run in "CPU mode", where the FPGA is not used and all inference is done on the CPU. This does not require a license and is useful for testing; however the throughput of the CPU is much lower. For details of how to run this, see the CAIMAN-ASR server documentation.

The directory containing the license file(s) is passed as an argument to the start_server script.