IBUFDS - 2024.1 English

UltraScale Architecture Libraries Guide (UG974)

Document ID
UG974
Release Date
2024-05-30
Version
2024.1 English

Primitive: Differential Input Buffer

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

Introduction

The usage and rules corresponding to the differential primitives are similar to the single-ended SelectIO primitives. Differential SelectIO primitives have two pins to and from the device pads to show the P and N channel pins in a differential pair. N channel pins have a B suffix.

I/O attributes that do not impact the logic function of the component, such as IOSTANDARD, DIFF_TERM, and IBUF_LOW_PWR, 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
I IB O
0 0 No Change
0 1 0
1 0 1
1 1 No Change

Port Descriptions

Port Direction Width Function
I Input 1 Diff_p Buffer Input. Connect to top-level p-side input port.
IB Input 1 Diff_n Buffer Input. Connect to top-level n-side input port.
O Output 1 Buffer output

Design Entry Method

Instantiation Recommended
Inference No
IP and IP Integrator Catalog No

VHDL Instantiation Template

Unless they already exist, copy the following two statements and paste them before the entity declaration.
Library UNISIM;
use UNISIM.vcomponents.all;

-- IBUFDS: Differential Input Buffer
--         UltraScale
-- Xilinx HDL Language Template, version 2024.1

IBUFDS_inst : IBUFDS
port map (
   O => O,   -- 1-bit output: Buffer output
   I => I,   -- 1-bit input: Diff_p buffer input (connect directly to top-level port)
   IB => IB  -- 1-bit input: Diff_n buffer input (connect directly to top-level port)
);

-- End of IBUFDS_inst instantiation

Verilog Instantiation Template


// IBUFDS: Differential Input Buffer
//         UltraScale
// Xilinx HDL Language Template, version 2024.1

IBUFDS IBUFDS_inst (
   .O(O),   // 1-bit output: Buffer output
   .I(I),   // 1-bit input: Diff_p buffer input (connect directly to top-level port)
   .IB(IB)  // 1-bit input: Diff_n buffer input (connect directly to top-level port)
);

// End of IBUFDS_inst instantiation

Related Information

  • UltraScale Architecture SelectIO Resources User Guide (UG571)
  • Vivado Design Suite Properties Reference Guide (UG912)