The period of machine cycle of an 8051 system with crystal freque
| The period of machine cycle of an 8051 system with crystal frequency 16 MHz is
A. 0.25 μs
B. 0.5 μs
C. 0.75 μs
D. 1 μs
Please scroll down to see the correct answer and solution guide.
Right Answer is: C
SOLUTION
Concept:
8051 Timers:
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 circuity of the 8051 microcontrollers provides a clock source to the timers that are 1/12th of the frequency of crystal attached, i.e.
Calculation:
Crystal Oscillator frequency = 16 MHz
∴ The Time Frequency will be:
\(f_T=\frac{1}{12}\times 16=\frac{4}{3}~MHz\)
The time period for the machine cycle will be:
\(T=\frac{1}{Timer~frequency}\)
\(T=\frac{3}{4}~μsec\)'
T = 0.75 μsec
