Primitive: I/O Weak Keeper
- PRIMITIVE_GROUP: I/O
- PRIMITIVE_SUBGROUP: WEAK_DRIVER
- Families: UltraScale, UltraScale+
Introduction
The design element is a weak keeper element that retains the value of the I/O when not being driven. For example, if a logic 1 is being driven onto the I/O, KEEPER drives a weak/resistive 1 onto the pin/port. If the net driver is then 3-stated, KEEPER continues to drive a weak/resistive 1 onto the pin/port.
Port Descriptions
| Port | Direction | Width | Function |
|---|---|---|---|
| O | Inout | 1 | Keeper output. Connect directly to a top_level port. |
Design Entry Method
| Instantiation | Yes |
| Inference | Yes, via property |
| 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;
-- KEEPER: I/O Weak Keeper
-- UltraScale
-- Xilinx HDL Language Template, version 2022.1
KEEPER_inst : KEEPER
port map (
O => O -- 1-bit inout: Keeper output (connect directly to top-level port)
);
-- End of KEEPER_inst instantiation
Verilog Instantiation Template
// KEEPER: I/O Weak Keeper
// UltraScale
// Xilinx HDL Language Template, version 2022.1
KEEPER KEEPER_inst (
.O(O) // 1-bit inout: Keeper output (connect directly to top-level port)
);
// End of KEEPER_inst instantiation
Related Information
- See the UltraScale Architecture SelectIO Resources User Guide (UG571).