What is the duration of the clock period for the machine cycle for 8051 microcontroller of 16 MHz crystal frequency?

Concept

Every timer needs a clock to work and 8051 provides it from an external crystal which is the main clock source for the timer.

The internal circuitry of the 8051 microcontrollers provides a clock source to the timers that are 1/12 of the frequency of the crystal attached.

Calculation

Crystal Oscillator frequency = 16 MHz

∴ The timer frequency is:

\(f_T={1\over 12}\times 16={4\over 3}\space MHz\)

The time period for the machine cycle will be:

\(T={1\over f_T}\)

\(T={3\over 4}\mu s\)

T = 0.75 \(\mu s\)