Properties

All the properties are well defined in their respective LPM module of chapter four. The following few properties are listed out due to it's universal nature among all LPM modules.

LPM_TYPE Property

LPM_TYPE property is required to identify the LPM cell type in cell definition. It appears as the string property called LPM_TYPE in the cell definition. For example, LPM_AND is the value of string property LPM_TYPE.

EDIF 2 0 0 example:

(cell and_4 (cellType generic) (view view1 (viewType netlist) (interface (port . . .) . . . (property LPM_TYPE (string "LPM_AND")) EDIF 3 0 0 example: (cell and_4 (cellHeader . . . (cluster C1 (interface (interfaceUnits) (port . . .) . . . (clusterHeader (property LPM_TYPE (string "LPM_AND"))

LPM_Polarity Property

The LPM_Polarity property can be attached to any port in the cell definition of an LPM module. It is a mechanism for inverting the polarity of the port. With this property control, inputs and output ports can be of either polarity (active high or active low. The default value of LPM_Polarity is positive active (no inversion done) and hence the only accepted value for this property is "INVERT" as shown in the following LPM fragment:

     (port clock
        (property LPM_Polarity (string "INVERT")))

LPM_Polarity property declaration is identical between EDIF 2 0 0 and EDIF 3 0 0.

LPM_Hint Property

This is an optional property that contains additional technology-specific information for use by the silicon vendor tools. There are no standard values for this field and it is up to the design tool vendors and the silicon tool vendors to utilize it as needed. The LPM_HINT property can always be ignored and the correct logic will be constructed, although it may not be constructed efficiently.