Primitive: Two input OR gate implemented in place of a CLB Latch
- PRIMITIVE_GROUP: CLB
- PRIMITIVE_SUBGROUP: LATCH
Introduction
This element allows the specification of a configurable CLB latch to take the function of a two input OR gate. The use of this element can reduce logic levels and increase logic density of the part by trading off register/latch resources for logic. Xilinx suggests caution when using this component as it can affect register packing and density within a CLB.
Logic Table
Inputs | Outputs | |
---|---|---|
DI | SRI | O |
0 | 0 | 0 |
0 | 1 | 1 |
1 | 0 | 1 |
1 | 1 | 1 |
Port Descriptions
Port | Direction | Width | Function |
---|---|---|---|
DI | Input | 1 | Active-High input that is generally connected to sourcing LUT located in the same CLB. |
O | Output | 1 | Output of the OR gate. |
SRI | Input | 1 | Input that is generally sourced from outside of the CLB. The attribute IS_SRI_INVERTED determines
the active polarity of this signal.
Note: To allow more than one AND2B1L or OR2L to be packed into
a half CLB, a common signal must be connected to this input.
|
Design Entry Method
Instantiation | Yes |
Inference | No |
IP and IP Integrator Catalog | No |
Available Attributes
Attribute | Type | Allowed Values | Default | Description |
---|---|---|---|---|
IS_SRI_INVERTED | BINARY | 1'b0 to 1'b1 | 1'b0 | Specifies whether or not to use the optional inversion for the SRI pin of this component. |
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;
-- OR2L: Two input OR gate implemented in place of a CLB Latch
-- Versal Prime series
-- Xilinx HDL Language Template, version 2022.1
OR2L_inst : OR2L
generic map (
IS_SRI_INVERTED => '0' -- Optional inversion for SRI
)
port map (
O => O, -- 1-bit output: OR gate output
DI => DI, -- 1-bit input: Data input connected to LUT logic
SRI => SRI -- 1-bit input: External CLB data
);
-- End of OR2L_inst instantiation
Verilog Instantiation Template
// OR2L: Two input OR gate implemented in place of a CLB Latch
// Versal Prime series
// Xilinx HDL Language Template, version 2022.1
OR2L #(
.IS_SRI_INVERTED(1'b0) // Optional inversion for SRI
)
OR2L_inst (
.O(O), // 1-bit output: OR gate output
.DI(DI), // 1-bit input: Data input connected to LUT logic
.SRI(SRI) // 1-bit input: External CLB data
);
// End of OR2L_inst instantiation
Related Information
- Versal ACAP Configurable Logic Block Architecture Manual (AM005)