OBUFT - 2025.1 English - Primitive: 3-State Output Buffer - UG974

UltraScale Architecture Libraries Guide (UG974)

Document ID
UG974
Release Date
2025-05-29
Version
2025.1 English

Primitive: 3-State Output Buffer

  • PRIMITIVE_GROUP: I/O
  • PRIMITIVE_SUBGROUP: OUTPUT_BUFFER
  • Families: UltraScale, UltraScale+

Introduction

The generic 3-state output buffer OBUFT typically implements 3-state outputs or bidirectional I/O.

I/O attributes that do not impact the logic function of the component, such as IOSTANDARD, DRIVE, and SLEW, should be supplied to the top-level port via an appropriate property. For details on applying such properties to the associated port, see the Vivado Design Suite Properties Reference Guide (UG912).

Logic Table

Inputs Outputs
T I O
1 X Z
0 1 1
0 0 0

Port Descriptions

Port Direction Width Function
I Input 1 Input of OBUF. Connect to the logic driving the output port.
O Output 1 Output of OBUF to be connected directly to top-level output port.
T Input 1 3-state enable input.

Design Entry Method

Instantiation Yes
Inference Recommended
IP and IP Integrator Catalog No

VHDL Instantiation Template

Verilog Instantiation Template

Related Information