Does an 8051 microcontroller need external oscillator to run?

does-an-8051-microcontroller-need-external-oscillator-to-run

Does an 8051 microcontroller need external oscillator to run?

A. True

B. False

I have been asked this question in examination.

My doubt stems from Microcontroller (8051- Pin, Registers, Timers) in chapter Prototyping Embedded Devices of IOT

The correct option is A. True

Easiest explanation: The 8051 has an on chip oscillator but requires an external oscillator clock to run it. Most often a quartz crystal oscillator is connected to inputs XTAL1 and XTAL2.