单片机的工作是在统一的脉冲控制下的进行的。这个脉冲就是由单片机控制器的

The work of the one-chip computer is carried on under the unified pulse control. This pulse is issued by the clock circuit of the single-chip controller, that is, the clock circuit is used to generate the clock signal required for the operation of the single-chip. The one-chip computer itself is a complicated synchronous sequential circuit, in order to guarantee the realization of the synchronous working mode, the circuit should work strictly according to the sequence under the control of the only clock signal. The clock circuit is used to generate the clock signal for the microcontroller. And the clock circuit is divided into two kinds respectively, namely internal clock mode and external clock mode. <br>This text design adopts the internal clock mode in this way, the one-chip computer connects a high gain inverting amplifier to form the internal oscillator. The pins XTAL1 and XTAL2 are the input and output terminals of this amplifier, respectively. At the same time, a crystal or ceramic resonator is connected across both ends of XTAL1 and XTAL2 to form a stable self-excited oscillator, and the pulse signal sent out is directly sent to the internal clock generator. The capacitors C5 and C6 are usually chosen to be (30+ or ​​-10) pf or so; when an external ceramic resonator is connected, it is chosen to be about 47 pf. Capacitors C5 and C6 have a fine-tuning effect on the frequency. In order to reduce the parasitic capacitance and better ensure the reliable operation of the oscillator, the resonator and capacitor should be installed as close as possible to the microcontroller chip. The internal clock generator is actually a divide-by-two flip-flop. The divide-by-two provides a two-phase clock signal for the microcontroller, namely phase signal 1 (P1) and phase signal 2 (P2), which drives the CPU to generate instructions for executing the instruction function. Machine cycle. Here we use a 12MHz crystal oscillator, which means that the clock cycle of the microcontroller is 1/12uS and the instruction cycle is 1uS. The higher the frequency of the crystal oscillator, the higher the oscillation frequency, as shown in Figure 3-14.

The work of the microcontroller is carried out under the unified pulse control. This pulse is emitted by the clock circuit of the microcontroller controller, i.e. the clock circuit is used to generate the clock signal required for the microcontroller to operate. The microcontroller itself is a complex synchronous timing circuit, in order to ensure the realization of synchronous working methods, the circuit should be under the control of the unique clock signal strictly on time and in time to work. The clock circuit is used to generate a clock signal for microcontroller operation. The clock circuit is divided into two kinds, namely, the internal clock mode and the external clock mode.<br>In this paper, an internal clock is designed to form an internal oscillator by attaching a high-gain reverse amplifier inside the microcontroller. Pins XTAL1 and XTAL2 are the inputs and outputs of this amplifier, respectively. At the same time, the XTAL1 and XTAL2 ends are joined with crystals or ceramic resonators to form a stable self-exciting oscillator, which sends pulsed signals directly to the internal clock generator. Capacitors C5 and C6 are usually selected around (30 plus or -10) pf, while external ceramic resonators are selected around 47pf. Capacitors C5 and C6 fine-tune the frequency. In order to reduce the parasitic capacitor and better ensure the reliable operation of the oscillator, the resonator and capacitor should be installed as close as possible to the microcontroller chip. The internal clock generator is actually a dicycle trigger that provides the microcontroller with a two-phase clock signal, Phase Signal 1 (P1) and Phase Signal 2 (P2), that drives the CPU to generate a machine cycle that performs instruction functions. Here we use a 12MHz crystal, which means that the clock cycle of the microcontroller is 1/12uS and the instruction period is 1uS. The higher the frequency of the crystal oscillator, the higher the frequency of oscillation, as shown in Figure 3-14.

The work of single chip microcomputer is carried out under the unified pulse control. The pulse is sent out by the clock circuit of MCU controller, and the real-time clock circuit is used to generate the clock signal needed by MCU. MCU itself is a complex synchronous sequential circuit. In order to ensure the realization of synchronous working mode, the circuit should work strictly according to the timing under the control of the only clock signal. The clock circuit is used to generate the clock signal of MCU. The clock circuit is divided into two kinds, namely internal clock mode and external clock mode.<br>In this paper, the internal clock mode is adopted. In this mode, a high gain reverse amplifier is connected to the MCU to form an internal oscillator. Xtal1 and xtal2 are the input and output of the amplifier respectively. At the same time, a stable self-excited oscillator is formed by bridging crystal or ceramic resonators at both ends of xtal1 and xtal2, and the pulse signal is directly sent to the internal clock generator. Capacitance C5 and C6 are usually about (30 + or - 10) PF; The external ceramic resonator is about 47pf. Capacitors C5 and C6 can fine tune the frequency. In order to reduce the parasitic capacitance and ensure the reliable operation of the oscillator, the resonator and capacitor should be installed as close as possible to the MCU chip. The internal clock generator is actually a two-phase trigger, which provides a two-phase clock signal for the MCU, namely phase signal 1 (P1) and phase signal 2 (P2), and drives the CPU to generate the machine cycle to execute the instruction function. Here we use a 12Mhz crystal oscillator, that is to say, the clock cycle of MCU is 1g12us, and the instruction cycle is 1US. The higher the frequency of the crystal oscillator, the higher the oscillation frequency, as shown in Figure 3-14.<br>