51 SCM Introduction

Clock cycle, or also called the beat, another called the state cycle S, there is a machine cycle and instruction cycle, which is a concept of several clocks in the single chip computer, wherein the clock cycle is also called the oscillation cycle, it is the inverse of the crystal frequency, for example, 12MHz crystal, this clock cycle is 12MHz one second, this is called a beat, Two beats make up a state period which is 1/12 times two, which is 1/6, which is 6 MHz one second, this is the state period. The machine cycle is composed of 12 clock cycles, the machine cycle is 12MHz times 12, 12MHz 1/12 times 12 is a microsecond, the instruction cycle is composed of machine cycles,

Ordinary 51 single chip microcomputer we call 12T single chip microcomputer, refers to the 12 clock cycles, that is, the 12 clock cycles of the single chip microcomputer, we called 12T single chip microcomputer. That is to say, it can only complete a basic micro-operation in 12 clock cycles, such as executing the simplest instruction, such as the note instruction, but now there are many single-chip computers are 1T single-chip computers, and of course, there are 2T single-chip computers, which is faster than our 12T single-chip computers. Because it can complete a basic operation in a clock cycle, and we need 12 clock cycles to complete, it is equivalent to doing the same thing ah, some people may need ten minutes to finish, but some people need 120 minutes to finish, that is, its efficiency is not the same, the speed of execution is not the same. This is what we have to figure out in these concepts.

Clock oscillator produced, for example, you are a 12 trillion crystal oscillator, produce a waveform, then the waveform is a second can oscillate 12 trillion times, 12 trillion times this is the frequency, its period, is 12 trillion, we call the clock period, or called the oscillation period, this is very easy to understand.