‌Design principer och praktiska tillämpningar av återställningar

The design principle of the reset circuit is to connect an external resistor and capacitor to the reset pin RST of the microcontroller to achieve power-on reset. The reset is valid when the reset level lasts for more than two machine cycles. Specifically, the microcontroller reset circuit consists of two parts: key reset and power-on reset. Power-on reset is achieved by connecting a capacitor to the Vcc terminal on the RST reset input pin and a resistor to the ground. When the microcontroller is powered on, the RST terminal will receive a short high-level signal, which will gradually fall back as Vcc charges the capacitor. In order to ensure that the system can be reset reliably, the high-level signal at the RST -terminalen måste underhållas under en tillräckligt lång tid .