Up to three additional hard memory controllers are available to logic in the FPGA depending on which SoC is used. These controllers have the same memory device support, performance, and operation as the controller in the HPS. The differences are that these controllers are not a part of the HPS and are designed for the exclusive use of logic in the FPGA. These controllers are more flexible in that the controller portion can be bypassed for those who wish to use a soft controller and need only the PHY and I/Os. For those who do not wish to use these controllers at all, they can be bypassed completely, providing general-purpose I/O functions instead.