IOBUFE3 - 2021.1 English

Primitive: Bidirectional I/O Buffer with Offset Calibration and VREF Tuning

PRIMITIVE_GROUP: I/O
PRIMITIVE_SUBGROUP: BIDIR_BUFFER

Introduction

The bidirectional input/output buffer primitive (IOBUFE3) is only supported in XP I/O banks. This primitive has functions similar to the IOBUF_DCIEN along with controls for offset calibration and V_REF 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 V_REF scan feature is accessed using the XPIO_VREF primitive in conjunction with IOBUFE3.

I/O attributes that do not impact the logic function of the component such as IOSTANDARD, DRIVE and IBUF_LOW_PWR should be supplied in XDC or 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
DCITERMDISABLE	Input	1	Control to enable/disable DCI termination. This is generally used to reduce power in long periods of an idle state.
I	Input	1	Input of OBUF. Connect to the logic driving the output port.
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.
IO	Inout	1	Bidirectional port to be connected directly to top-level inout port.
O	Output	1	Output path of the buffer.
OSC<3:0>	Input	4	Offset cancellation value
OSC_EN	Input	1	Offset cancellation enable
T	Input	1	3-state enable input signifying whether the buffer acts as an input or output.
VREF	Input	1	Vref input from HPIO_VREF

Design Entry Method

Instantiation	Yes
Inference	No
IP and IP Integrator Catalog	No

Available Attributes

Attribute	Type	Allowed Values	Default	Description
SIM_DEVICE	STRING	"VERSAL_PRIME", "VERSAL_PRIME_ES1", "VERSAL_PRIME_ES2"	"ULTRASCALE"	Set the device version for simulation functionality.
SIM_INPUT_BUFFER_OFFSET	DECIMAL	-50 to 50	0	Offset value for simulation purposes.
USE_IBUFDISABLE	STRING	"FALSE", "T_CONTROL", "TRUE"	"FALSE"	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;


-- IOBUFE3: Bidirectional I/O Buffer with Offset Calibration and VREF Tuning
--          Versal Prime series
-- Xilinx HDL Language Template, version 2021.1

IOBUFE3_inst : IOBUFE3
generic map (
   SIM_DEVICE => "VERSAL_PRIME", -- Set the device version for simulation functionality (VERSAL_PRIME,
                                 -- VERSAL_PRIME_ES1)
   SIM_INPUT_BUFFER_OFFSET => 0, -- Offset value for simulation (-50-50)
   USE_IBUFDISABLE => "FALSE"    -- Enable/Disable the IBUFDISABLE pin (FALSE, TRUE, T_CONTROL)
)
port map (
   O => O,                           -- 1-bit output: Buffer output
   DCITERMDISABLE => DCITERMDISABLE, -- 1-bit input: DCI Termination Disable
   I => I,                           -- 1-bit input: Buffer input
   IBUFDISABLE => IBUFDISABLE,       -- 1-bit input: Buffer disable input, high=disable
   IO => IO,                         -- 1-bit inout: Buffer inout (connect directly to top-level port)
   OSC => OSC,                       -- 4-bit input: Offset cancellation value
   OSC_EN => OSC_EN,                 -- 1-bit input: Offset cancellation enable
   T => T,                           -- 1-bit input: 3-state enable input
   VREF => VREF                      -- 1-bit input: Vref input from HPIO_VREF
);

-- End of IOBUFE3_inst instantiation

Verilog Instantiation Template


// IOBUFE3: Bidirectional I/O Buffer with Offset Calibration and VREF Tuning
//          Versal Prime series
// Xilinx HDL Language Template, version 2021.1

IOBUFE3 #(
   .SIM_DEVICE("VERSAL_PRIME"), // Set the device version for simulation functionality (VERSAL_PRIME,
                                // VERSAL_PRIME_ES1)
   .SIM_INPUT_BUFFER_OFFSET(0), // Offset value for simulation (-50-50)
   .USE_IBUFDISABLE("FALSE")    // Enable/Disable the IBUFDISABLE pin (FALSE, TRUE, T_CONTROL)
)
IOBUFE3_inst (
   .O(O),                           // 1-bit output: Buffer output
   .DCITERMDISABLE(DCITERMDISABLE), // 1-bit input: DCI Termination Disable
   .I(I),                           // 1-bit input: Buffer input
   .IBUFDISABLE(IBUFDISABLE),       // 1-bit input: Buffer disable input, high=disable
   .IO(IO),                         // 1-bit inout: Buffer inout (connect directly to top-level port)
   .OSC(OSC),                       // 4-bit input: Offset cancellation value
   .OSC_EN(OSC_EN),                 // 1-bit input: Offset cancellation enable
   .T(T),                           // 1-bit input: 3-state enable input
   .VREF(VREF)                      // 1-bit input: Vref input from HPIO_VREF
);

// End of IOBUFE3_inst instantiation

Related Information

Versal ACAP SelectIO Resources Architecture Manual (AM010)