IBUFDSE3 and IBUFDSE3_XP5 - IBUFDSE3 and IBUFDSE3_XP5 - UG861

Spartan UltraScale+ FPGAs SelectIO Resources User Guide (UG861)

Document ID
UG861
Release Date
2026-04-28
Revision
1.1 English

The differential input buffer (IBUFDSE3) primitive is only supported in HP I/O banks (see the following figure). This UltraScale architecture specific primitive has functions similar to the IBUFDS_IBUFDISABLE and IBUFDS_IBUFDISABLE_XP5 along with controls for offset calibration and input buffer disable (IBUFDISABLE). The offset calibration feature is accessed using the OSC_EN[1:0] and OSC[3:0] ports. The VREF scan feature is not supported with this primitive.

Figure 1. IBUFDSE3 Primitive—Differential Input Buffer with Offset Calibration (HP I/O Banks Only)

The differential input buffer (IBUFDSE3_XP5) primitive is only supported in XP5IO I/O banks.

Note: IBUFDSE3 and IBUFDSE3_XP5 I/O buffers have similar functionality but are differentiated due to IBUFDISABLE functionality differences. HP I/O banks drive the O pin Low when IBUFDISABLE is asserted High, while XP5IO I/O banks assert the O pin High when IBUFDISABLE is asserted.