Issue link: https://resources.pcb.cadence.com/i/1180526
PSpice User Guide Digital device modeling October 2019 391 Product Version 17.4-2019 © 1999-2019 All Rights Reserved. within the implementation of the digital primitives within the simulator. Therefore, they are not user-selectable. Inertial delay The simulation of a device may be described as the application of some stimulus (S) to a function (F) and predicting the response (R). If this device is electrical in nature, application of the stimulus implies that energy will be imparted to the device to cause it to change state. The amount of such energy is a function of the signal's amplitude and duration. If the stimulus is applied to the device for a length of time that is too short, the device will not switch. The minimum duration required for an input change to have an effect on a device's output state is called the inertial delay of the device. For digital simulation, all delay parameters specified in timing models are considered inertial, with the exception of the delay line primitive, DLYLINE. To model the noise immunity behavior of digital devices correctly, the TPWRT (pulse width rejection threshold) parameter can be set in the digital device's I/O model. When pulse width ≥ TPWRT and pulse width < propagation delay, then the device generates either a 0-R-0, 1-F-1, or an X pulse. This example shows normal operation in which a pulse of 20 nsec width is applied to a BUF primitive having propagation delays of 10 nsec. TPWRT is not set. S F TPLHTY=10 20 40 30 50 TPHLTY=10 (TPWRT not set)