Hi sandro.c.grech, Welcome to EasyEDA. Sorry but you cannot simulate the whole of a processor in EasyEDA. It would be too big to deal with in XSPICE (see the ngspice manual: <http://ngspice.sourceforge.net/docs/ngspice-manual.pdf#chapter.12>) and EasyEDA does not support VHDL / Verilog simulation. If you need to do VHDL / Verilog simulation, you could try this: <http://iverilog.com/> With some thought, you can often simplify the functions that the processor is carrying out or strip a complex set of operations down to some basic steps that can then be modelled as a simple set of functions. For example a processor might be used to sense the leight level from a light dependent resistor and turn a light on when the light level drops below a certain threshold and then turn the light off after a certain time. If what you actually want to model is the operation of the LDR input circuit and the lamp driver output then that could simply be modelled by a comparator with an input that models the processor input followed by a monostable with an output that models how the processor output is configured, driving the lamp driver. It is also simulate functions of processors such as a comparator or ADC input, a PWM or a DAC output or a state machine using XPSICE. Simple functions can often be simulated using behavioural models built from B sources: <https://easyeda.com/Doc/Simulation-eBook/B-sources.htm#Bsourcesspicesimulation> Sets of PULSE() and/or PWL() sources can be configured to generate sequences of signals that can represent sequential logic outputs. XSPICE devices are already available for use in EasyEDA but you may need help in setting up the more advanced devices. A simple example is here: <https://easyeda.com/editor#id=GSM4mEWew> A new family of logic devices is being added to EasyEDA to assist in modelling simpler logic functions. Some of thse devices will be in the next release.

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