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FUNCTION LCELL (in) RETURNS (out);
COMPONENT LCELL PORT (a_in : IN STD_LOGIC; a_out: OUT STD_LOGIC); END COMPONENT;
The LCELL
buffer allocates a logic cell for the project. The LCELL
buffer produces the true and the complement of a logic function and makes both available to all logic in the device. (The output of the LCELL
buffer must feed through a NOT
gate to use the complement of the logic function.)
An LCELL
buffer always consumes one logic cell. It is not removed from a project during logic synthesis.
Do not use LCELL primitives to create an intentional delay or asynchronous pulse. The delay of these elements varies with temperature, power supply voltage, and device fabrication process, so race conditions can occur and create an unreliable circuit. |
You can turn on the Implement as Output of Logic Cell logic option to insert LCELL
buffers at strategic points in the project logic. When you turn on the Ignore LCELL Buffers logic option, the Compiler automatically converts all LCELL
buffers to WIRE
primitives.
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