Standard-cell recognition or 'functional abstraction' refers to the process of automatically deducing the abstract logical behavior of a CMOS circuit based on the transistor-level netlist. This methods find applications in verification, reverse engineering and automated design tools such as tools for Standard-cell characterization.
An algorithm for CMOS functional abstraction can be found in .
The remainder of this section illustrates a very similar algorithm.
Recognizing combinational CMOS logic
Recognizing sequential CMOS logic
State-full CMOS logic necessarily has feedback loops. A feedback loop can have several characteristic properties: a) It can be stable and keep it's state, b) it can be transparent and copy the state of the input data signal if the write condition is met, c) it can oscillate or cause a short (e.g. an odd-numbers of inverters connected in a circle). Recognizing sequential logic involves detecting the feedback loops and finding their data inputs, outputs and write conditions.
- Anthony Lester, Pirouz Bazargan-Sabet, Alain Greiner, YAGLE, a Second generation Functional Abstractor for CMOS VLSI Circuits, https://dx.doi.org/10.1109/ICM.1998.825615