Introduction¶
In this part of the project, you will make some electrical simulations of the designed cell in order to extract usefull model parameters for frontend tools like
synthesizers
timing analyzers
place & route tools
These model parameters are not constant values that can be measured using a single electrical simulation of the cell. Theses values are functions of input parameters such as:
The choosen case for the technological process
The choosen power supply value
The choosen temperature
The rise/fall time of the input signals
The rise/fall time of the input clocks
The capacitive load connected at the outputs.
Analytical models of these parameters are to complex to be setup, frontend tools use “tabulated models”. The values of the parameters are extracted from multiple electrical simulations of the cell with various values of the input parameters..
Furthermore, in order do ensure a correct usage of the tabulated models, some bounds have to be setup for the input parameters: the frontend tools will be asked to use the chararcterized cell within the defined bounds.
Choosen parameters for all simulations¶
For the current project, the following parameters will not change:
Technological process : Typical Case
Power supply: 1.1V
Temperature: 25°
For the current project, the following parameters will be bounded:
Maximum rise/fall time of any “non-clock” signal: 200ps
Maximum rise/fall time of any “clock” signal: 100ps
The maximum capacitive load connected at the output of a gate, is the capacitive load giving a output signal with the maximum rise/fall time !!!