Advanced Embedded Systems Interview Question:

Tell me how much time is required by an instruction for execution in 8051?

Submitted by: Muhammad

☛ Time required depends on the number of clock cycles used to execute instruction.
☛ These clock cycle are called machine cycle.
☛ Length of machine cycle of an instruction depends on frequency of crystal oscillator of controller.
☛ Also one machine cycle lasts 12 oscillator period so machine cycle is 1 12 of crystal frequency.
☛ Crystal frequency 8051 = 11.0592MHz
☛ Machine cycle = 11.0592MHz12 = 921.6KHz = 1.085micro second.
Submitted by: Muhammad