Representation of the Parasitic

Parasitic representation

DSPF: Detailed standard parasitics Format
RSPF: Reduced standard parasitics Format
SPEF: Standard parasitic extraction Format

• Standard parasitics Extraction Format interconnect parasitics depend on process. SPEF supports the specification of best-case, typical, and worst-case values. 
• These triplets are allowed for R, L and C values, port slews and loads. By providing a name map consisting of a map of net names and instance names to indices, the SPEF file size is made effectively smaller, and more importantly, all long names appear in only one place.

DSPF: Detailed standard parasitics Format:

• Detailed parasitics are represented in SPICE format, SPICE Comment statements are used to indicate the cell type, pin capacitance
• The resistance and capacitance values are in standard SPICE syntax and the cell instantiations are also included in this representation. 
• Merits:
• DSPF file can be used as an input to a SPICE simulator itself. 
• Drawback
• The DSPF syntax is too detailed and verbose with the result that the total file size for a typical block is very large.

RSPF: Reduced standard parasitics Format

• These parasitics are represented in reduced format and it involves in voltage-controlled current sources.
• Detailed parasitics are reduced and mapped into Reduced format it can be read into SPICE Simulators
• Drawbacks:
• Not represented for bidirectional signal flow