Standard Parasitic Exchange Format (SPEF) is an IEEE standard for representing parasitic data of wires in a chip in ASCII format. SPEF is most popular specification for parasitic exchange between different tools of EDA domain during any phase of design.
SPEF is an Open Verilog Initiatve (OVI)--and now IEEE--format for defining netlist parasitics. SPEF is NOT identical to the SPF format, although it is used in a similar manner. Like the SPF format, SPEF includes resistance and capacitance parasitics. Also like the SPF format, SPEF can represent parasitic in detailed or reduced (pi-model) forms, with the reduced form probably being more commonly used. SPEF also has a syntax that allows the modeling of capacitance between different nets, so it is used by the PrimeTime SI (crosstalk) analysis tool. SPEF is smaller than SPF and DSPF because the names are mapped to integers to reduce file size.
Standard Parasitic Format (SPF). SPF is a Cadence Design Systems standard for defining netlist parasitics. DSPF and RSPF are the two forms of SPF; the term SPF itself is sometimes used (or misused) to represent parasitics in general. DSPF and RSPF both represent parasitic information as an RC network.