5 

DEF Writer Callback Routines

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

When you use callback routines, the writer creates a DEF 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	yes	yes
Bus Bit Characters	yes	yes
Divider	yes	yes
Design	yes	no
Technology	no	no
Units	no	no
History	no	no
Property Definition	no	no
Die Area	no	no
Rows	no	no
Tracks	no	no
Gcell Grid	no	no
Vias	no	no
Regions	no	no
Components	yes	no
Pins	no	no
Pin Properties	no	no
Special Nets	no	no
Nets	yes	no
Scan chains	no	no
Groups	no	no
Extensions	no	no
Design End	yes	no

Callback Function Format

All callback functions use the following format.

int UserCallbackFunctions(

defwCallbackType_e callBackType,

defiUserData 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 DEF data.

User Data

The data argument is a four-byte data item that you set. The DEF 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 DEF writer callback-setting routines and the associated callback types.

DEF Information	Setting Routine	Callback Types
Blockages	void defwSetBlockageCbk (defwVoidCbkFnType)	defwBlockageCbkType
Bus Bit Characters	void defwSetBusBitCbk (defwVoidCbkFnType)	defwBusBitCbkType
Components	void defwSetComponentCbk (defwVoidCbkFnType)	defwComponentCbkType
Design	void defwSetDesignCbk (defwVoidCbkFnType)	defwDesignCbkType
Design End	void defwSetDesignEndCbk (defwVoidCbkFnType)	defwDesignEndCbkType
Die Area	void defwSetDieAreaCbk (defwVoidCbkFnType)	defwDieAreaCbkType
Divider	void defwSetDividerCbk (defwVoidCbkFnType)	defwDividerCbkType
Extensions	void defwSetExtCbk (defwVoidCbkFnType)	defwExtCbkType
Gcell Grid	void defwSetGcellGridCbk (defwVoidCbkFnType)	defwGcellGridCbkType
Groups	void defwSetGroupCbk (defwVoidFnType)	defwGroupCbkType
History	void defwSetHistoryCbk (defwVoidCbkFnType)	defwHistoryCbkType
Nets	void defwSetNetCbk (defwVoidCbkFnType)	defwNetCbkType
Pins	void defwSetPinCbk (defwVoidCbkFnType)	defwPinCbkType
Pin Properties	void defwSetPinPropCbk (defwVoidCbkFnType)	defwPinPropCbkType
Property Definitions	void defwSetPropDefCbk (defwVoidCbkFnType)	defwPropDefCbkType
Regions	void defwSetRegionCbk (defwVoidCbkFnType)	defwRegionCbkType
Rows	void defwSetRowCbk (defwVoidCbkFnType)	defwRowCbkType
Special Nets	void defwSetSNetCbk (defwVoidCbkFnType)	defwSNetCbkType
Scan Chains	void defwSetScanchainCbk (defwVoidCbkFnType)	defwScanchainCbkType
Technology	void defwSetTechnologyCbk (defwVoidCbkFnType)	defwTechCbkType
Tracks	void defwSetTrackCbk (defwVoidCbkFnType)	defwTrackCbkType
Units	void defwSetUnitsCbk (defwVoidCbkFnType)	defwUnitsCbkType
Version	void defwSetVersionCbk (defwVoidCbkFnType)	defwVersionCbkType
Vias	void defwSetViaCbk (defwVoidCbkFnType)	defwViaCbkType