The bidirectional input/output buffer primitive (IOBUFE3) is supported in HP and XP5IO I/O banks (see the following figure). This UltraScale+ architecture specific primitive has functions similar to the IOBUF_DCIEN along with controls for offset calibration and VREF tuning with input buffer disable (IBUFDISABLE) and on-die input termination control (DCITERMDISABLE) for the input buffer. The offset calibration feature is accessed using the OSC_EN and OSC[3:0] ports. The VREF scan feature is accessed using the HPIO_VREF primitive with IOBUFE3.
Figure 1. IOBUFE3 Primitive—Bidirectional I/O Buffer with Offset Calibration and
VREF Tuning (HP I/O Banks Only)
