IBUF_INTERMDISABLE - 2023.1 English

UltraScale Architecture Libraries Guide (UG974)

Document ID
UG974
Release Date
2023-05-17
Version
2023.1 English

Primitive: Input Buffer With Input Buffer Disable and On-die Input Termination Disable

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

Introduction

The IBUF_INTERMDISABLE primitive is available in the HR I/O banks and is similar to the IBUF_IBUFDISABLE primitive in that it has a IBUFDISABLE port that can be used to disable the input buffer during periods that the buffer is not being used. The USE_IBUFDISABLE attribute must be set to TRUE and SIM_DEVICE to the appropriate value for this primitive to have the expected behavior specific to the architecture. The IBUF_INTERMDISABLE primitive also has an INTERMDISABLE port that can be used to disable the optional on-die receiver termination feature. See the UltraScale Architecture SelectIO Resources User Guide (UG571), "Uncalibrated Input Termination in I/O Banks" for more details.

The IBUF_INTERMDISABLE primitive can disable the input buffer and force the O output to the internal logic to a logic-Low when the IBUFDISABLE signal is asserted High. The IBUF_INTERMDISABLE primitive further allows the termination legs to be disabled whenever the INTERMDISABLE signal is asserted High. These features can be combined to reduce power whenever the input is idle. Input buffers that use the VREF power rail (such as SSTL and HSTL) benefit the most from the IBUFDISABLE signal being set to TRUE because they tend to have higher static power consumption than the non-VREF standards such as LVCMOS and LVTTL.

I/O attributes that do not impact the logic function of the component, such as IOSTANDARD 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).

Port Descriptions

Port Direction Width Function
I Input 1 Input port connection. Connect directly to top-level port in the design.
IBUFDISABLE Input 1 Disables input path through the buffer and forces to a logic Low. This feature is generally used to reduce power at times when the I/O is idle for a period of time.
INTERMDISABLE Input 1 Control to enable/disable of on-chip input termination. This is generally used to reduce power in long periods of an idle state.
O Output 1 Buffer output representing the input path to the device.

Design Entry Method

Instantiation Yes
Inference No
IP and IP Integrator Catalog No

Available Attributes

Attribute Type Allowed Values Default Description
SIM_DEVICE STRING "7SERIES", "ULTRASCALE" "7SERIES" Set the device version for simulation functionality.
USE_IBUFDISABLE STRING "TRUE", "FALSE" "TRUE" Set this attribute to "TRUE" to enable the IBUFDISABLE pin.

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;

-- IBUF_INTERMDISABLE: Input Buffer With Input Buffer Disable and On-die Input Termination Disable
--                     UltraScale
-- Xilinx HDL Language Template, version 2023.1

IBUF_INTERMDISABLE_inst : IBUF_INTERMDISABLE
generic map (
   SIM_DEVICE => "ULTRASCALE", -- Set the device version for simulation functionality (ULTRASCALE)
   USE_IBUFDISABLE => "TRUE"   -- Enable/Disable the IBUFDISABLE pin (FALSE, TRUE)
)
port map (
   O => O,                         -- 1-bit output: Buffer output
   I => I,                         -- 1-bit input: Buffer input (connect directly to top-level port)
   IBUFDISABLE => IBUFDISABLE,     -- 1-bit input: Buffer disable input, high=disable
   INTERMDISABLE => INTERMDISABLE  -- 1-bit input: Input Termination Disable
);

-- End of IBUF_INTERMDISABLE_inst instantiation

Verilog Instantiation Template


// IBUF_INTERMDISABLE: Input Buffer With Input Buffer Disable and On-die Input Termination Disable
//                     UltraScale
// Xilinx HDL Language Template, version 2023.1

IBUF_INTERMDISABLE #(
   .SIM_DEVICE("ULTRASCALE"), // Set the device version for simulation functionality (ULTRASCALE)
   .USE_IBUFDISABLE("TRUE")   // Enable/Disable the IBUFDISABLE pin (FALSE, TRUE)
)
IBUF_INTERMDISABLE_inst (
   .O(O),                         // 1-bit output: Buffer output
   .I(I),                         // 1-bit input: Buffer input (connect directly to top-level port)
   .IBUFDISABLE(IBUFDISABLE),     // 1-bit input: Buffer disable input, high=disable
   .INTERMDISABLE(INTERMDISABLE)  // 1-bit input: Input Termination Disable
);

// End of IBUF_INTERMDISABLE_inst instantiation

Related Information

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