Primitive

LCELL Primitive



AHDL Function Prototype (port name and order also apply to Verilog HDL):

FUNCTION LCELL (in)
   RETURNS (out);


VHDL Component Declaration:

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.

NOTE 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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