[51] Do i need to add an external oscillator in real life to AT89c51 ?

[94d33m]

I have been doing simulations with it but in some practical circuit i see some oscillator on the 18 and 19th pin. In simulation I dont find any model for the the oscillator though.What happens if i dont add it in real life?

 

[srizbf]

If you dont connect any crystal in 8051 in real circuit , it will not work.