I/O Buffer (ALTIOBUF) Megafunction User Guide: Known Issues - I/O Buffer (ALTIOBUF) Megafunction User Guide: Known Issues Description Issue 75663 , Version 3.0 Table 2-1 states Use differential mode is not available for Cyclone® III, Cyclone IV, and Cyclone V devices. This is incorrect; this option is available for all families that support the ALTIOBUF megafunction. Issue 379237 , version 10.1 The IOE delay cell values are not correct for Stratix V devices. For more information on the number of delay chain settings, the minimum offset, and the incremental delay for the IOE delay cells, refer to the IOE Programmable Delay for Stratix V devices in the DC and Switching Characteristics for Stratix V Devices (PDF) . Resolution . Custom Fields values: ['novalue'] Troubleshooting NA False ['novalue'] ['novalue'] novalue novalue ['Stratix® V E FPGA', 'Stratix® V FPGAs', 'Stratix® V GS FPGA', 'Stratix® V GT FPGA', 'Stratix® V GX FPGA'] ['novalue'] ['novalue'] ['novalue']