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LEF Writer Callback Routines

You can use the Cadence^® Library Exchange Format (LEF) writer with callback routines, or you can call one writer function at a time.

When you use callback routines, the writer creates a LEF file in the sequence shown in the following table. The writer also checks which sections are required for the file. If you do not provide a callback for a required section, the writer uses a default routine. If no default routine is available for a required section, the writer generates an error message.

Section	Required	Default Available
Version	no	no
Bus Bit Characters	no	no
Divider Character	no	no
Units	no	no
Property Definitions	no	no
Layer	yes	no
Via	yes	no
Via Rule	yes	no
Nondefault Rules	no	no
Spacing	no	no
Site	yes	no
Macro	yes	no
Extensions	no	no
End Library	yes	no

Callback Function Format

All callback functions use the following format.

int UserCallbackFunctions(

lefwCallbackType_e callBackType,

lefiUserData data)

Callback Type

The callBackType argument is a list of objects that contains a unique number assignment for each callback from the parser. This list allows you to use the same callback routine for different types of LEF data.

User Data

The data argument is a four-byte data item that you set. The LEF writer contains only user data. The user data is most often set to a pointer to the design data so that it can be passed to the routines.

Callback Types and Setting Routines

The following table lists the LEF writer callback-setting routines and the associated callback types.

LEF Information	Setting Routine	Callback Types
Bus Bit Characters	void lefwSetBusBitCharsCbk (lefwVoidCbkFnType);	lefwBusBitCharsCbkType
Clearance Measure	void lefwSetClearanceMeasureCbk (lefwVoidCbkFnType);	lefwClearanceMeasureCbkType
Divider Character	void lefwSetDividerCharCbk (lefwVoidCbkFnType);	lefwDividerCharCbkType
Extensions	void lefwSetExtCbk (lefwVoidCbkFnType);	lefwExtCbkType
End Library	void lefwSetEndLibCbk (lefwVoidCbkFnType);	lefwEndLibCbkType
Layer	void lefwSetLayerCbk (lefwVoidCbkFnType);	lefwLayerCbkType
Macro	void lefwSetMacroCbk (lefwVoidCbkFnType);	lefwMacroCbkType
Manufacturing Grid	void lefwSetManufacturingGridCbk (lefwVoidCbkFnType);	lefwManufacturingGridCbkType
Nondefault Rule	void lefwSetNonDefaultCbk (lefwVoidCbkFnType);	lefwNonDefaultCbkType
Property Definitions	void lefwSetPropDefCbk (lefwVoidCbkFnType);	lefwPropDefCbkType
Site	void lefwSetSiteCbk (lefwVoidCbkFnType);	lefwSiteCbkType
Spacing	void lefwSetSpacingCbk (lefwVoidCbkFnType);	lefwSpacingCbkType
Units	void lefwSetUnitsCbk (lefwVoidCbkFnType);	lefwUnitsCbkType
Use Min Spacing	void lefwSetUseMinSpacingCbk (lefwVoidCbkFnType);	lefwUseMinSpacingCbkType
Version	void lefwSetVersionCbk (lefwVoidCbkFnType);	lefwVersionCbkType
Via	void lefwSetViaCbk (lefwVoidCbkFnType);	lefwViaCbkType
Via Rule	void lefwSetViaRuleCbk (lefwVoidCbkFnType);	lefwViaRuleCbkType