BUFGCE - BUFGCE - 2025.2 English - Primitive: General Clock Buffer with Clock Enable

Primitive: General Clock Buffer with Clock Enable

PRIMITIVE_GROUP: CLOCK
PRIMITIVE_SUBGROUP: BUFFER

Introduction

This design element is a general clock buffer with a single gated input. When clock enable (CE) is Low (inactive), its O output is 0. When CE is High, the I input is transferred to the O output.

Logic Table

Inputs		Outputs
I	CE	O
X	0	0
I	1	I

Port Descriptions

Port	Direction	Width	Function
CE	Input	1	Clock buffer active-High enable.
I	Input	1	Buffer input.
O	Output	1	Buffer output.

Design Entry Method

Instantiation	Recommended
Inference	Yes
IP and IP Integrator Catalog	No

Available Attributes

Attribute	Type	Allowed Values	Default	Description
CE_TYPE	STRING	"SYNC", "ASYNC", "HARDSYNC"	"SYNC"	Specifies whether the enable should be synchronous (glitch-free) or asynchronous (no input clock switching necessary). Versal devices have a an optional hardened synchronizer circuit that can be enabled by using the HARDSYNC setting.
IS_CE_INVERTED	BINARY	1'b0 to 1'b1	1'b0	Specifies use of the programmable inversion on the CE pin.
IS_I_INVERTED	BINARY	1'b0 to 1'b1	1'b0	Specifies use of the programmable inversion on the I pin.
SIM_DEVICE	STRING	"ULTRASCALE", "ULTRASCALE_PLUS"	"ULTRASCALE"	Set the device version

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;


-- BUFGCE: General Clock Buffer with Clock Enable
--         Spartan UltraScale+
-- Xilinx HDL Language Template, version 2025.2

BUFGCE_inst : BUFGCE
generic map (
   CE_TYPE => "SYNC",               -- ASYNC, HARDSYNC, SYNC
   IS_CE_INVERTED => '0',           -- Programmable inversion on CE
   IS_I_INVERTED => '0',            -- Programmable inversion on I
   SIM_DEVICE => "ULTRASCALE_PLUS"  -- ULTRASCALE, ULTRASCALE_PLUS
)
port map (
   O => O,   -- 1-bit output: Buffer
   CE => CE, -- 1-bit input: Buffer enable
   I => I    -- 1-bit input: Buffer
);

-- End of BUFGCE_inst instantiation

Verilog Instantiation Template


// BUFGCE: General Clock Buffer with Clock Enable
//         Spartan UltraScale+
// Xilinx HDL Language Template, version 2025.2

BUFGCE #(
   .CE_TYPE("SYNC"),               // ASYNC, HARDSYNC, SYNC
   .IS_CE_INVERTED(1'b0),          // Programmable inversion on CE
   .IS_I_INVERTED(1'b0),           // Programmable inversion on I
   .SIM_DEVICE("ULTRASCALE_PLUS")  // ULTRASCALE, ULTRASCALE_PLUS
)
BUFGCE_inst (
   .O(O),   // 1-bit output: Buffer
   .CE(CE), // 1-bit input: Buffer enable
   .I(I)    // 1-bit input: Buffer
);

// End of BUFGCE_inst instantiation

Related Information

UltraScale Architecture Clocking Resources User Guide (UG572)

BUFGCE - BUFGCE - 2025.2 English - Primitive: General Clock Buffer with Clock Enable - UG1704

Spartan UltraScale+ Libraries Guide (UG1704)