Right-click an FPGA I/O item in the Project Explorer window and select Select Resource from the shortcut menu to display this dialog box.
Use this dialog box to view the I/O resources available for the FPGA target under which the FPGA I/O item appears in the Project Explorer window. Select an I/O resource in the tree to change the I/O resource to which the FPGA I/O item is assigned. You might need to select a new FPGA I/O resource if you copy the FPGA I/O item from another FPGA target in the Project Explorer window.